CWebView2

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CWebView2

Hosts a Microsoft Edge browser in a window and drives it from tiko code.

CWebView2 puts a WebView2 control, the Chromium-based Edge engine, inside a window or control of your program: it shows web pages, HTML you build as a string and local files, runs JavaScript in them and exchanges messages with them. One object owns the three COM objects the browser is made of: the environment (the browser processes and the profile folder), the controller (the control in your window: size, visibility, focus, zoom) and the WebView itself (navigation, scripts, events). The raw interfaces are there too, for everything the class does not wrap; see WebView2 interfaces.

What it needs at run time. Two things must be on the machine that runs the program:

the WebView2 Runtime, the shared Edge engine. Windows 11 has it built in; on Windows 10 it is installed with Edge or on its own. GetAvailableCoreWebView2BrowserVersionString says whether, and which version, is there.
WebView2Loader.dll, the small loader that finds the runtime. Nothing links against it: each call that needs it loads it by name, with the normal DLL search (the program's own folder first, then the folders on PATH), calls it and frees it again. Ship a copy next to your .exe; the toolchain has one in examples/win64/WebView2 Examples/. When it is missing, those calls return E_POINTER and the browser never starts.

Creation is asynchronous. The constructor only asks for the environment; the runtime answers later through callbacks, while the thread pumps messages, and only then do the controller and the WebView exist. Call IsReady after the constructor: it pumps messages until the browser is there. Until then every method that checks returns E_POINTER; the ones marked needs a ready WebView below do not check and must not be called before.

The host window. The constructor stores the object's address in the host window's GWLP_USERDATA slot, which is how CWebView2Ptr finds it again in a window procedure; do not use that slot for anything else. The browser is created visible and as large as the host's client area at that moment; resize it on WM_SIZE with SetBounds. Bounds are in the host's client coordinates, in pixels.

Lifetime. The object must outlive the window: declare it in main before DoEvents, as the example does, never in a procedure that returns. The constructor initialises COM on the thread (single-threaded apartment); the destructor closes the browser, releases the three objects and uninitialises COM.

Results. Each wrapper returns the HRESULT of the call it makes and stores it, so GetLastResult and GetErrorInfo can tell what went wrong, including after the methods that return a value. Text that the runtime returns is copied into a ustring and its memory freed for you.

The three interface pointers and the stored values are public fields: m_Result, m_hWnd, m_pEnv, m_pController, m_pCoreWebView2 and m_BrowserVersion.

Importing

#import "sys/win"
#import "sys/win/webview2"
using win, webview2

A program that creates its window with CWindow imports sys/win/gui too.

Example

A window that shows a page built from a string, with a button whose click the page posts back to the program, which puts it in the caption:

#import "sys/win"
#import "sys/win/gui"
#import "sys/win/webview2"
using win, gui, webview2

declare function WndProc( byval hwnd as HWND, byval uMsg as UINT, byval wParam as WPARAM, byval lParam as LPARAM ) as LRESULT

' Shows each string the page posts in the window caption
type MessageHandler extends CWebView2WebMessageReceivedEventHandler
    declare function Invoke( byval sender as ICoreWebView2 ptr, byval args as ICoreWebView2WebMessageReceivedEventArgs ptr ) as HRESULT
    m_hwnd as HWND
end type

function MessageHandler.Invoke( byval sender as ICoreWebView2 ptr, byval args as ICoreWebView2WebMessageReceivedEventArgs ptr ) as HRESULT
    dim pwszMsg as LPWSTR
    if args->TryGetWebMessageAsString( @pwszMsg ) = S_OK then
        SetWindowTextW( m_hwnd, pwszMsg )
        CoTaskMemFree( pwszMsg )
    end if
    return S_OK
end function

function main() as long
    SetProcessDpiAwareness( PROCESS_SYSTEM_DPI_AWARE )
    dim pWindow as CWindow = "WebView2Demo"
    dim hWin as HWND = pWindow.Create( NULL, "CWebView2", @WndProc )
    pWindow.SetClientSize( 640, 400 )
    pWindow.Center

    ' the browser fills the client area of hWin; its profile goes to a folder of its own
    dim pWebView2 as CWebView2 = CWebView2( hWin, GetTempPath() & "WebView2Demo" )
    if pWebView2.IsReady( 10000 ) = false then
        MessageBoxW( hWin, "The WebView2 Runtime did not start.", "CWebView2", MB_ICONERROR )
        return 1
    end if

    dim pHandler as MessageHandler ptr = new MessageHandler
    pHandler->m_hwnd = hWin
    dim token as EventRegistrationToken
    pWebView2.AddWebMessageReceived( cast( any ptr, pHandler ), @token )
    pWebView2.AreDefaultContextMenusEnabled( false )

    pWebView2.NavigateToString( _
        "<body style='font: 16px Segoe UI'><h2>Hello from tiko</h2>" & _
        "<button onclick=""window.chrome.webview.postMessage('Clicked at ' + new Date().toLocaleTimeString())"">" & _
        "Post a message</button></body>" )
    pWebView2.MoveFocus( COREWEBVIEW2_MOVE_FOCUS_REASON_PROGRAMMATIC )

    return pWindow.DoEvents( SW_NORMAL )
end function

function WndProc( byval hwnd as HWND, byval uMsg as UINT, byval wParam as WPARAM, byval lParam as LPARAM ) as LRESULT
    select case uMsg
        case WM_SIZE
            ' keep the browser the size of the client area
            dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
            if pWebView2 then
                dim rc as RECT
                GetClientRect( hwnd, @rc )
                pWebView2->SetBounds( rc )
            end if
            return 0
        case WM_DESTROY
            PostQuitMessage( 0 )
            return 0
    end select
    return DefWindowProcW( hwnd, uMsg, wParam, lParam )
end function

end main()

Put WebView2Loader.dll next to the program before running it. The handler is created with new and never deleted by the program: the WebView holds a reference to it and the object deletes itself when the WebView lets it go. More programs (images, video, maps, charts, SVG) are in the toolchain's examples/win64/WebView2 Examples/ folder.

Members

Member	Does
Constructor	Starts creating a browser in a window, with the default or a separate profile.
Destructor	Closes the browser and releases it.
IsReady	Pumps messages until the browser exists, or a time-out passes.
GetHWnd	Returns the host window.
GetTopLevelWindow	Returns the top-level window the host belongs to.
GetBrowserVersion	Returns the version of the runtime in use.
GetLastResult	Returns the stored result code.
SetResult	Stores a result code.
GetErrorInfo	Describes a result code in words.
GetWebViewPtr	Returns the `ICoreWebView2` interface.
GetControllerPtr	Returns the `ICoreWebView2Controller` interface.
GetEnvironmentPtr	Returns the `ICoreWebView2Environment` interface.
GetCoreWebView2	Returns the `ICoreWebView2` interface with a reference added.
LoadFileAsJSInlineScript	Turns a script file into a JavaScript expression that yields a data URL.
LoadImageAsDataURL	Turns an image file into a `data:` URL.
LoadImageAsUint8Array	Turns a file into JavaScript `Uint8Array` source text.
Navigate	Loads a URL.
NavigateToString	Shows HTML given as a string.
Stop	Stops loading.
Reload	Loads the current page again.
GoBack	Goes back in the history.
GoForward	Goes forward in the history.
CanGoBack	Says whether there is a page to go back to.
CanGoForward	Says whether there is a page to go forward to.
GetSource	Returns the URL of the current page.
GetBrowserProcessId	Returns the process id of the browser process.
GetIsVisible, SetIsVisible	Read or set whether the browser is shown.
GetBounds, SetBounds	Read or set where the browser is in the host window.
GetZoomFactor, SetZoomFactor	Read or set the zoom.
GetParentWindow, SetParentWindow	Read or change the host window.
MoveFocus	Gives the keyboard focus to the page.
NotifyParentWindowPositionChanged	Tells the browser that the host window moved.
Close	Closes the browser now.
ExecuteScript	Runs JavaScript in the current page.
PostWebMessageAsJson	Sends a JSON message to the page.
PostWebMessageAsString	Sends a string message to the page.
AddScriptToExecuteOnDocumentCreated	Runs a script at the start of every page loaded from now on.
RemoveScriptToExecuteOnDocumentCreated	Stops running such a script.
AddHostObjectToScript	Makes a COM object of the program visible to the page's JavaScript.
RemoveHostObjectFromScript	Withdraws such an object.
CapturePreview	Saves an image of what the browser shows.
OpenDevToolsWindow	Opens the developer tools.
CallDevToolsProtocolMethod	Runs a DevTools Protocol method.
GetDevToolsProtocolEventReceiver	Returns a receiver for a DevTools Protocol event.
GetContainsFullScreenElement	Says whether an element of the page is full screen.
AddWebResourceRequestedFilter, RemoveWebResourceRequestedFilter	Choose which requests raise WebResourceRequested.
GetSettings	Returns the `ICoreWebView2Settings` interface.
IsScriptEnabled	Reads or sets whether pages run JavaScript.
IsWebMessageEnabled	Reads or sets whether messages pass between page and program.
AreDefaultScriptDialogsEnabled	Reads or sets whether `alert`, `confirm` and `prompt` show their own dialogs.
IsStatusBarEnabled	Reads or sets whether link targets show in a status bar.
AreDevToolsEnabled	Reads or sets whether the user can open the developer tools.
AreDefaultContextMenusEnabled	Reads or sets whether the right-click menu appears.
AreHostObjectsAllowed	Reads or sets whether pages can reach host objects.
IsZoomControlEnabled	Reads or sets whether the user can zoom.
IsBuiltInErrorPageEnabled	Reads or sets whether failed loads show the built-in error page.
AddNavigationStarting, RemoveNavigationStarting	Handle the start of each top-level navigation.
AddNavigationCompleted, RemoveNavigationCompleted	Handle the end of each top-level navigation.
AddFrameNavigationStarting, RemoveFrameNavigationStarting	Handle the start of a navigation in a frame.
AddFrameNavigationCompleted, RemoveFrameNavigationCompleted	Handle the end of a navigation in a frame.
AddContentLoading, RemoveContentLoading	Handle the start of loading a new document.
AddSourceChanged, RemoveSourceChanged	Handle a change of the current URL.
AddHistoryChanged, RemoveHistoryChanged	Register a SourceChanged handler (see the entry).
AddScriptDialogOpening, RemoveScriptDialogOpening	Handle `alert`, `confirm`, `prompt` and `beforeunload` dialogs.
AddPermissionRequested, RemovePermissionRequested	Answer a page's requests for the camera, location and so on.
AddProcessFailed, RemoveProcessFailed	Handle a crashed or ended browser process.
AddWebMessageReceived, RemoveWebMessageReceived	Receive the messages the page posts.
AddNewWindowRequested, RemoveNewWindowRequested	Handle a page opening a new window.
AddDocumentTitleChanged, RemoveDocumentTitleChanged	Handle a change of the page title.
AddContainsFullScreenElementChanged, RemoveContainsFullScreenElementChanged	Handle an element entering or leaving full screen.
AddWebResourceRequested, RemoveWebResourceRequested	Inspect or answer the requests that match a filter.
AddWindowCloseRequested, RemoveWindowCloseRequested	Handle `window.close()` in the page.
AddZoomFactorChanged, RemoveZoomFactorChanged	Handle a change of zoom.
AddMoveFocusRequested, RemoveMoveFocusRequested	Handle Tab or Shift+Tab leaving the page.
AddGotFocus, RemoveGotFocus	Handle the browser getting the focus.
AddLostFocus, RemoveLostFocus	Handle the browser losing the focus.
AddAcceleratorKeyPressed, RemoveAcceleratorKeyPressed	See shortcut keys before the page does.

Reference

Constructor

constructor()
constructor( byval hWin as HWND, byval pUserDataFolder as wstring ptr = NULL )
constructor( byval hWin as HWND, byref ustrUserDataFolder as ustring )

Initialises COM on the thread, stores the object's address in hWin's GWLP_USERDATA slot and asks the runtime for an environment. The call returns at once; the browser appears in hWin once the runtime has answered, which IsReady waits for. Its result, the HRESULT of the request, is stored for GetLastResult: E_POINTER when hWin is NULL (nothing else happens then) or when WebView2Loader.dll cannot be loaded.

dim pWebView2 as CWebView2 = hWin, or a NULL folder, uses the default profile: a folder named after the program with .WebView2 added (MyApp.exe.WebView2), next to the .exe. Creation fails when the program cannot create that folder, for example under Program Files.
A folder gives the browser a separate profile there: its own cookies, cache and storage. The ustring form always passes the folder on, even an empty string.

The default constructor does nothing: no COM, no window, no browser. It exists for the helper methods, such as LoadImageAsDataURL, that need no browser.

Parameter	Meaning
`hWin`	The host: a window or control whose client area the browser fills.
`pUserDataFolder`, `ustrUserDataFolder`	The profile folder, absolute or relative to the program's folder; created if it does not exist.

Example

dim pWebView2 as CWebView2 = CWebView2( hwnd, GetTempPath() & "MyAppWebView2" )
if pWebView2.IsReady( 10000 ) then pWebView2.Navigate( "https://example.com" )

Microsoft Learn: CreateCoreWebView2EnvironmentWithOptions, user data folders

Destructor

destructor()

Releases the WebView, closes and releases the controller, releases the environment and uninitialises COM on the thread. Closing ends the browser processes this object started once no other WebView uses them.

The destructor calls CoUninitialize whichever constructor ran, including the default one, which did not initialise COM.

Example

scope
    dim pWebView2 as CWebView2 = hwnd
    if pWebView2.IsReady( 5000 ) then pWebView2.Navigate( "https://example.com" )
end scope   ' the browser closes here

Microsoft Learn: ICoreWebView2Controller::Close

IsReady

function IsReady( byval dwMaxWaitMilliseconds as long = -1 ) as boolean

Waits until the browser exists: it pumps the thread's messages, so that the runtime's callbacks can run, every 50 ms or whenever a message arrives, until the controller has been created or dwMaxWaitMilliseconds have passed. When the browser is already there it returns after that first wait of at most 50 ms.

With the default -1 it waits without limit, and when creation fails (no runtime, no loader, a profile folder that cannot be created) the callbacks never deliver a controller, so it never returns: pass a time-out. Messages it dispatches go to their windows as usual; a WM_QUIT it meets is removed and lost.

Parameter	Meaning
`dwMaxWaitMilliseconds`	The most milliseconds to wait, or -1 for no limit.

Returns true when the browser is ready, false when the time ran out.

Example

dim pWebView2 as CWebView2 = hwnd
if pWebView2.IsReady( 10000 ) = false then print "no WebView2 Runtime?"

Microsoft Learn: MsgWaitForMultipleObjects

GetHWnd

function GetHWnd() as HWND

Returns the host window given to the constructor or to SetParentWindow, or NULL.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
InvalidateRect( pWebView2->GetHWnd(), NULL, true )

GetTopLevelWindow

function GetTopLevelWindow() as HWND

Goes up from the host window, through parents for child windows and owners for the others, until a window has neither.

Returns that window, the host itself when it is a top-level window, or NULL when the host is not a window.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hCtrl )
SetWindowTextW( pWebView2->GetTopLevelWindow(), "Loaded" )

GetBrowserVersion

function GetBrowserVersion() as ustring

Returns the version of the WebView2 Runtime the environment uses, such as 156.0.4314.58, read when the environment was created; "" before that.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
print "runtime "; pWebView2->GetBrowserVersion()

Microsoft Learn: ICoreWebView2Environment::get_BrowserVersionString

GetLastResult

function GetLastResult() as HRESULT

Returns the result code of the last wrapper called: S_OK (0) on success, E_POINTER (&h80004003) for a call made before the browser was ready, otherwise the runtime's error.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
dim nZoom as double = pWebView2->GetZoomFactor()
if pWebView2->GetLastResult() <> S_OK then print pWebView2->GetErrorInfo()

SetResult

function SetResult( byval Result as HRESULT ) as HRESULT

Stores Result as the last result code, for code that calls the raw interfaces itself and wants GetLastResult and GetErrorInfo to report it.

Returns Result.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
pWebView2->SetResult( pWebView2->GetWebViewPtr()->Reload() )

GetErrorInfo

function GetErrorInfo( byval nError as long = -1 ) as ustring

Describes a result code in the language of Windows. For a code other than 0 the text starts with Error &h and the code in hexadecimal, then a line break and the description; each part ends with a line break.

Parameter	Meaning
`nError`	The code to describe; -1 (the default) describes the last result code.

Returns the text; for E_FAIL that is Error &h80004005, a line break, Unspecified error and a line break. An unknown code gives the first line only.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
if pWebView2->Navigate( "https://example.com" ) <> S_OK then print pWebView2->GetErrorInfo()

Microsoft Learn: FormatMessageW

GetWebViewPtr

function GetWebViewPtr() as ICoreWebView2 ptr

Returns the object's own ICoreWebView2 pointer, or NULL before the browser is ready. No reference is added: do not release it. Use it for what the class does not wrap; its later versions (ICoreWebView2_2 …) are reached with QueryInterface.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
dim pCore as ICoreWebView2 ptr = pWebView2->GetWebViewPtr()
if pCore then pCore->OpenDevToolsWindow()

Microsoft Learn: ICoreWebView2

GetControllerPtr

function GetControllerPtr() as ICoreWebView2Controller ptr

Returns the object's own ICoreWebView2Controller pointer, or NULL before the browser is ready. No reference is added: do not release it.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
dim pCtl as ICoreWebView2Controller ptr = pWebView2->GetControllerPtr()
if pCtl then pCtl->put_ZoomFactor( 1.25 )

Microsoft Learn: ICoreWebView2Controller

GetEnvironmentPtr

function GetEnvironmentPtr() as ICoreWebView2Environment ptr

Returns the object's own ICoreWebView2Environment pointer, or NULL before the runtime has answered. No reference is added: do not release it.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
dim pEnv as ICoreWebView2Environment ptr = pWebView2->GetEnvironmentPtr()
if pEnv = NULL then print "the environment has not been created"

Microsoft Learn: ICoreWebView2Environment

GetCoreWebView2

function GetCoreWebView2() as ICoreWebView2 ptr

Asks the controller for its WebView. Needs a ready WebView.

Returns an ICoreWebView2 pointer with a reference added, which you release, or NULL when the call fails.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
dim pCore as ICoreWebView2 ptr = pWebView2->GetCoreWebView2()
if pCore then pCore->Reload() : pCore->Release()

Microsoft Learn: ICoreWebView2Controller::get_CoreWebView2

LoadFileAsJSInlineScript

function LoadFileAsJSInlineScript( byref ustrPath as ustring ) as string

Reads a file, makes a data:application/javascript;base64,… URL of it and returns JavaScript source text that rebuilds that URL as a string: new TextDecoder('latin1').decode(Uint8Array.from([100,97,116,97,…])), the bytes of the URL as decimal numbers. The base64 part keeps the line breaks the encoder puts after every 64 characters, and the decoded string ends with a carriage return, a line feed and a NUL character. Needs no browser.

Parameter	Meaning
`ustrPath`	The file.

Returns the expression, or "" when the file cannot be opened or read.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
dim s as string = pWebView2->LoadFileAsJSInlineScript( "chart.umd.min.js" )
pWebView2->ExecuteScript( "var src = " & s & ";" )

LoadImageAsDataURL

function LoadImageAsDataURL( byref ustrPath as ustring ) as string

Reads a file and returns it as a data: URL, data:image/png;base64,…, ready for the src of an <img>. The type comes from the extension: .jpg and .jpeg, .png, .gif, .bmp and .webp; any other leaves it empty (data:;base64,…). The base64 text has no line breaks; the string ends with a NUL character. Needs no browser.

Returns the URL, or "" when the file cannot be opened or read or is empty. A three-byte file small.png holding ABC gives data:image/png;base64,QUJD and the NUL, 27 characters.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
dim s as string = pWebView2->LoadImageAsDataURL( "photo.jpg" )
pWebView2->NavigateToString( "<img src='" & s & "'>" )

Microsoft Learn: CryptBinaryToStringA

LoadImageAsUint8Array

function LoadImageAsUint8Array( byref ustrPath as ustring ) as string

Reads a file and returns JavaScript source text that builds a Uint8Array of its bytes: new Uint8Array([65,66,67]) for a file holding ABC. Any kind of file works; needs no browser. A read error is not checked. An empty file gives new Uint8Array([, without the closing brackets.

Returns the expression, or "" when the file cannot be opened.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
dim s as string = pWebView2->LoadImageAsUint8Array( "photo.png" )
pWebView2->ExecuteScript( "const bytes = " & s & "; console.log(bytes.length);" )

Navigate

function Navigate( byval uri as LPCWSTR ) as HRESULT

Starts loading uri in the browser: an https://, http:// or file:/// URL. The call returns before the page has loaded; AddNavigationCompleted tells when it has.

Returns S_OK when the navigation started; E_INVALIDARG for a URL that is not well formed; E_POINTER before the browser is ready.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
pWebView2->Navigate( "https://learn.microsoft.com/en-us/microsoft-edge/webview2/" )

Microsoft Learn: ICoreWebView2::Navigate

NavigateToString

function NavigateToString( byval htmlContent as LPCWSTR ) as HRESULT

Shows htmlContent as a new document. The runtime limits the HTML to about 2 MB; for more, save it with SaveTempHtmlFile and Navigate to the file.

Returns the HRESULT; E_POINTER before the browser is ready.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
pWebView2->NavigateToString( "<h1>Hello</h1><p>From a string.</p>" )

Microsoft Learn: ICoreWebView2::NavigateToString

Stop

function Stop() as HRESULT

Stops every navigation and resource download in progress. Scripts keep running.

Returns the HRESULT; E_POINTER before the browser is ready.

Example

CWebView2Ptr( hwnd )->Stop()

Microsoft Learn: ICoreWebView2::Stop

Reload

function Reload() as HRESULT

Loads the current page again.

Returns the HRESULT; E_POINTER before the browser is ready.

Example

CWebView2Ptr( hwnd )->Reload()

Microsoft Learn: ICoreWebView2::Reload

GoBack

function GoBack() as HRESULT

Goes to the previous page of the history; nothing happens when there is none.

Returns the HRESULT; E_POINTER before the browser is ready.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
if pWebView2->CanGoBack() then pWebView2->GoBack()

Microsoft Learn: ICoreWebView2::GoBack

GoForward

function GoForward() as HRESULT

Goes to the next page of the history; nothing happens when there is none.

Returns the HRESULT; E_POINTER before the browser is ready.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
if pWebView2->CanGoForward() then pWebView2->GoForward()

Microsoft Learn: ICoreWebView2::GoForward

CanGoBack

function CanGoBack() as boolean

Returns true when there is a previous page in the history; false otherwise and before the browser is ready.

Example

EnableWindow( hCtrl, CWebView2Ptr( hwnd )->CanGoBack() )

Microsoft Learn: ICoreWebView2::get_CanGoBack

CanGoForward

function CanGoForward() as boolean

Returns true when there is a next page in the history; false otherwise and before the browser is ready.

Example

EnableWindow( hCtrl, CWebView2Ptr( hwnd )->CanGoForward() )

Microsoft Learn: ICoreWebView2::get_CanGoForward

GetSource

function GetSource() as ustring

Returns the URL of the current top-level document, or "" before the browser is ready.

Example

SetWindowTextW( hwnd, CWebView2Ptr( hwnd )->GetSource() )

Microsoft Learn: ICoreWebView2::get_Source

GetBrowserProcessId

function GetBrowserProcessId() as UINT32

Returns the process id of the browser process behind this WebView, or 0 before the browser is ready.

Example

print "browser process"; CWebView2Ptr( hwnd )->GetBrowserProcessId()

Microsoft Learn: ICoreWebView2::get_BrowserProcessId

GetIsVisible, SetIsVisible

function GetIsVisible() as boolean
function SetIsVisible( byval isVisible as boolean ) as HRESULT

Read or set whether the browser is shown. A hidden browser does not paint and uses less processor time; the constructor shows it. Hide it, for instance, while the host window is minimised.

Returns GetIsVisible: true when shown, false when hidden or before the browser is ready. SetIsVisible: the HRESULT, E_POINTER before the browser is ready.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
pWebView2->SetIsVisible( not pWebView2->GetIsVisible() )

Microsoft Learn: ICoreWebView2Controller::put_IsVisible

GetBounds, SetBounds

function GetBounds() as RECT
function SetBounds( byval bounds as RECT ) as HRESULT

Read or set the rectangle the browser takes up in the host window, in the host's client coordinates, in pixels. The constructor sets it to the host's client area; call SetBounds on WM_SIZE to keep it so.

Returns GetBounds: the rectangle, all zeros before the browser is ready. SetBounds: the HRESULT, E_POINTER before the browser is ready.

Example

dim rc as RECT
GetClientRect( hwnd, @rc )
rc.top += 40                          ' leave room for a toolbar
CWebView2Ptr( hwnd )->SetBounds( rc )

Microsoft Learn: ICoreWebView2Controller::put_Bounds

GetZoomFactor, SetZoomFactor

function GetZoomFactor() as double
function SetZoomFactor( byval zoomFactor as double ) as HRESULT

Read or set the zoom of the page, 1.0 for 100 %. It applies to this browser only and stays in force across navigations.

Returns GetZoomFactor: the zoom, 0 before the browser is ready. SetZoomFactor: the HRESULT, E_POINTER before the browser is ready.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
pWebView2->SetZoomFactor( pWebView2->GetZoomFactor() * 1.1 )

Microsoft Learn: ICoreWebView2Controller::put_ZoomFactor

GetParentWindow, SetParentWindow

function GetParentWindow() as HWND
function SetParentWindow( byval parentWindow as HWND ) as HRESULT

Read the window the browser draws in, or move the browser to another window. On success SetParentWindow also stores the object's address in the new window's GWLP_USERDATA slot and makes it the host that GetHWnd returns; the old window's slot keeps the address. Set the bounds again afterwards: they are kept as they were, now relative to the new window.

Returns GetParentWindow: the window, or NULL before the browser is ready. SetParentWindow: the HRESULT, E_POINTER before the browser is ready.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
if pWebView2->SetParentWindow( hCtrl ) = S_OK then SetWindowLongPtrW( hwnd, GWLP_USERDATA, 0 )

Microsoft Learn: ICoreWebView2Controller::put_ParentWindow

MoveFocus

function MoveFocus( byval reason as COREWEBVIEW2_MOVE_FOCUS_REASON ) as HRESULT

Gives the keyboard focus to the browser. COREWEBVIEW2_MOVE_FOCUS_REASON_PROGRAMMATIC puts it back where it was in the page; …_NEXT and …_PREVIOUS put it on the first or last element, as Tab and Shift+Tab arriving from outside would.

Returns the HRESULT; E_POINTER before the browser is ready.

Example

CWebView2Ptr( hwnd )->MoveFocus( COREWEBVIEW2_MOVE_FOCUS_REASON_PROGRAMMATIC )

Microsoft Learn: ICoreWebView2Controller::MoveFocus

NotifyParentWindowPositionChanged

function NotifyParentWindowPositionChanged() as HRESULT

Tells the browser that the host window, or one of its ancestors, has moved on the screen, so that pop-ups such as drop-down lists open in the right place. Call it on WM_MOVE and WM_MOVING of the top-level window.

Returns the HRESULT; E_POINTER before the browser is ready.

Example

CWebView2Ptr( hwnd )->NotifyParentWindowPositionChanged()

Microsoft Learn: ICoreWebView2Controller::NotifyParentWindowPositionChanged

Close

function Close() as HRESULT

Closes the browser now, ending its processes once no other WebView uses them. Afterwards the controller's and the WebView's methods fail; the destructor still releases the objects.

Returns the HRESULT; E_POINTER before the browser is ready.

Example

CWebView2Ptr( hwnd )->Close()

Microsoft Learn: ICoreWebView2Controller::Close

ExecuteScript

function ExecuteScript( byval javaScript as LPCWSTR, byval handler as ICoreWebView2ExecuteScriptCompletedHandler ptr = NULL ) as HRESULT

Runs javaScript in the current top-level document. It runs later, after the call returns; when handler is given, its Invoke receives the error code and the value of the script's last expression as JSON (null for undefined).

Parameter	Meaning
`javaScript`	The script.
`handler`	Optional: an object derived from `CWebView2ExecuteScriptCompletedHandler`, passed as `cast( any ptr, p )`.

Returns the HRESULT of starting the script; E_POINTER before the browser is ready.

Example

CWebView2Ptr( hwnd )->ExecuteScript( "document.body.style.background = 'lightyellow';" )

Microsoft Learn: ICoreWebView2::ExecuteScript

PostWebMessageAsJson

function PostWebMessageAsJson( byval webMessageAsJson as LPCWSTR ) as HRESULT

Sends a message to the top-level document. The page receives it as a message event on window.chrome.webview, with event.data the JSON already parsed into a JavaScript value. Needs IsWebMessageEnabled, the default.

Returns the HRESULT; E_POINTER before the browser is ready.

Example

CWebView2Ptr( hwnd )->PostWebMessageAsJson( "{""count"": 3, ""name"": ""tiko""}" )

Microsoft Learn: ICoreWebView2::PostWebMessageAsJson

PostWebMessageAsString

function PostWebMessageAsString( byval webMessageAsString as LPCWSTR ) as HRESULT

Sends a plain string to the top-level document: event.data is that string.

Returns the HRESULT; E_POINTER before the browser is ready.

Example

CWebView2Ptr( hwnd )->PostWebMessageAsString( "refresh" )

Microsoft Learn: ICoreWebView2::PostWebMessageAsString

AddScriptToExecuteOnDocumentCreated

function AddScriptToExecuteOnDocumentCreated( byval javaScript as LPCWSTR, byval handler as ICoreWebView2AddScriptToExecuteOnDocumentCreatedCompletedHandler ptr ) as HRESULT

Adds a script that runs in every document loaded from now on, top-level and frames, before the document's own scripts. The handler's Invoke receives the script's id, which RemoveScriptToExecuteOnDocumentCreated takes.

Parameter	Meaning
`javaScript`	The script.
`handler`	An object derived from `CWebView2AddScriptToExecuteOnDocumentCreatedCompleteHandler`, passed as `cast( any ptr, p )`.

Returns the HRESULT; E_POINTER before the browser is ready.

Example

dim pHandler as CWebView2AddScriptToExecuteOnDocumentCreatedCompleteHandler ptr = new CWebView2AddScriptToExecuteOnDocumentCreatedCompleteHandler
CWebView2Ptr( hwnd )->AddScriptToExecuteOnDocumentCreated( "window.isHosted = true;", cast( any ptr, pHandler ) )

Microsoft Learn: ICoreWebView2::AddScriptToExecuteOnDocumentCreated

RemoveScriptToExecuteOnDocumentCreated

function RemoveScriptToExecuteOnDocumentCreated( byval id as LPCWSTR ) as HRESULT

Stops running the script with id id in documents loaded from now on.

Returns the HRESULT; E_POINTER before the browser is ready.

Example

dim ustrScriptId as ustring = "1"     ' the id the completion handler received
CWebView2Ptr( hwnd )->RemoveScriptToExecuteOnDocumentCreated( ustrScriptId )

Microsoft Learn: ICoreWebView2::RemoveScriptToExecuteOnDocumentCreated

AddHostObjectToScript

function AddHostObjectToScript( byval _name as LPCWSTR, byval _object as VARIANT ptr ) as HRESULT

Makes _object, normally an IDispatch object of the program in a VARIANT, reachable from the page's JavaScript as chrome.webview.hostObjects.<name> (asynchronous proxies) and chrome.webview.hostObjects.sync.<name>. Needs AreHostObjectsAllowed, the default. Needs a ready WebView.

Returns the HRESULT.

Example

dim v as VARIANT
v.vt = VT_I4 : v.lVal = 42
CWebView2Ptr( hwnd )->AddHostObjectToScript( "answer", @v )

Microsoft Learn: ICoreWebView2::AddHostObjectToScript

RemoveHostObjectFromScript

function RemoveHostObjectFromScript( byval _name as LPCWSTR ) as HRESULT

Withdraws the host object _name: new script calls to it fail. Needs a ready WebView.

Returns the HRESULT.

Example

CWebView2Ptr( hwnd )->RemoveHostObjectFromScript( "answer" )

Microsoft Learn: ICoreWebView2::RemoveHostObjectFromScript

CapturePreview

function CapturePreview( byval imageFormat as COREWEBVIEW2_CAPTURE_PREVIEW_IMAGE_FORMAT, byval imageStream as IStream ptr, byval handler as ICoreWebView2CapturePreviewCompletedHandler ptr ) as HRESULT

Writes an image of what the browser shows, as PNG (COREWEBVIEW2_CAPTURE_PREVIEW_IMAGE_FORMAT_PNG) or JPEG (…_JPEG), to imageStream. The image is written later; the handler's Invoke says when, with the error code.

Parameter	Meaning
`imageFormat`	PNG or JPEG.
`imageStream`	The stream to write to, such as one from `SHCreateStreamOnFileEx` or `CreateStreamOnHGlobal`.
`handler`	An object derived from `CWebView2AddCapturePreviewCompletedHandler`, passed as `cast( any ptr, p )`.

Returns the HRESULT of starting the capture; E_POINTER before the browser is ready.

Example

dim pStream as IStream ptr
SHCreateStreamOnFileEx( "page.png", STGM_CREATE or STGM_WRITE, FILE_ATTRIBUTE_NORMAL, true, NULL, @pStream )
dim pHandler as CWebView2AddCapturePreviewCompletedHandler ptr = new CWebView2AddCapturePreviewCompletedHandler
CWebView2Ptr( hwnd )->CapturePreview( COREWEBVIEW2_CAPTURE_PREVIEW_IMAGE_FORMAT_PNG, pStream, cast( any ptr, pHandler ) )

Microsoft Learn: ICoreWebView2::CapturePreview

OpenDevToolsWindow

function OpenDevToolsWindow() as HRESULT

Opens the developer tools window for the current document, even when AreDevToolsEnabled keeps the user from opening it.

Returns the HRESULT; E_POINTER before the browser is ready.

Example

CWebView2Ptr( hwnd )->OpenDevToolsWindow()

Microsoft Learn: ICoreWebView2::OpenDevToolsWindow

CallDevToolsProtocolMethod

function CallDevToolsProtocolMethod( byval methodName as LPCWSTR, byval parametersAsJson as LPCWSTR, byval handler as ICoreWebView2CallDevToolsProtocolMethodCompletedHandler ptr ) as HRESULT

Runs a method of the Chrome DevTools Protocol, such as Network.clearBrowserCache or Emulation.setDeviceMetricsOverride, with its parameters as a JSON object. The handler's Invoke receives the error code and the method's result as JSON. Needs a ready WebView.

Returns the HRESULT of starting the call.

Example

dim pHandler as CWebView2CallDevToolsProtocolMethodCompletedHandler ptr = new CWebView2CallDevToolsProtocolMethodCompletedHandler
CWebView2Ptr( hwnd )->CallDevToolsProtocolMethod( "Network.clearBrowserCache", "{}", cast( any ptr, pHandler ) )

Microsoft Learn: ICoreWebView2::CallDevToolsProtocolMethod

GetDevToolsProtocolEventReceiver

function GetDevToolsProtocolEventReceiver( byval eventName as LPCWSTR, byval receiver as ICoreWebView2DevToolsProtocolEventReceiver ptr ptr ) as HRESULT

Gets the receiver for one DevTools Protocol event, such as Runtime.consoleAPICalled. Add a CWebView2DevToolsProtocolEventReceivedEventHandler to it with its add_DevToolsProtocolEventReceived, and turn the event on with CallDevToolsProtocolMethod (for this one Runtime.enable). Release the receiver when done. Needs a ready WebView.

Returns the HRESULT.

Example

dim pReceiver as ICoreWebView2DevToolsProtocolEventReceiver ptr
if CWebView2Ptr( hwnd )->GetDevToolsProtocolEventReceiver( "Runtime.consoleAPICalled", @pReceiver ) = S_OK then
    pReceiver->Release()
end if

Microsoft Learn: ICoreWebView2::GetDevToolsProtocolEventReceiver

GetContainsFullScreenElement

function GetContainsFullScreenElement( byval ContainsFullScreenElement as long ptr ) as HRESULT
function GetContainsFullScreenElement() as long

Says whether an element of the page, such as a video, has asked to go full screen. The browser does not resize itself: a program that wants full screen handles AddContainsFullScreenElementChanged and makes the host window fill the screen. Needs a ready WebView.

Returns the first form: the HRESULT, with the answer (nonzero for yes) in the variable. The second: the answer, with the HRESULT kept for GetLastResult.

Example

if CWebView2Ptr( hwnd )->GetContainsFullScreenElement() then print "full screen"

Microsoft Learn: ICoreWebView2::get_ContainsFullScreenElement

AddWebResourceRequestedFilter, RemoveWebResourceRequestedFilter

function AddWebResourceRequestedFilter( byval uri as LPCWSTR, byval ResourceContext as COREWEBVIEW2_WEB_RESOURCE_CONTEXT ) as HRESULT
function RemoveWebResourceRequestedFilter( byval uri as LPCWSTR, byval ResourceContext as COREWEBVIEW2_WEB_RESOURCE_CONTEXT ) as HRESULT

Add or remove a filter: requests whose URL matches uri (* matches any run of characters) and whose kind is ResourceContext (COREWEBVIEW2_WEB_RESOURCE_CONTEXT_IMAGE, …_DOCUMENT, …_ALL …) raise the WebResourceRequested event, where the program can inspect them or answer them itself. These forms do not reach requests made from frames; the runtime's later interface has forms that do. Needs a ready WebView.

Returns the HRESULT.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
pWebView2->AddWebResourceRequestedFilter( "*.png", COREWEBVIEW2_WEB_RESOURCE_CONTEXT_IMAGE )
pWebView2->RemoveWebResourceRequestedFilter( "*.png", COREWEBVIEW2_WEB_RESOURCE_CONTEXT_IMAGE )

Microsoft Learn: ICoreWebView2::AddWebResourceRequestedFilter

GetSettings

function GetSettings() as ICoreWebView2Settings ptr

Gets the settings object of the browser, for settings that have no property below.

Returns an ICoreWebView2Settings pointer with a reference added, which you release, or NULL before the browser is ready.

Example

dim pSettings as ICoreWebView2Settings ptr = CWebView2Ptr( hwnd )->GetSettings()
if pSettings then pSettings->put_IsStatusBarEnabled( false ) : pSettings->Release()

Microsoft Learn: ICoreWebView2Settings

IsScriptEnabled

property IsScriptEnabled() as boolean
property IsScriptEnabled( byval enabled as boolean ) as HRESULT

The settings below are properties, each with a getter and a setter. Call the setter with the value in parentheses, IsScriptEnabled( false ): it returns the HRESULT. Before the browser is ready the getter returns false and the setter E_POINTER.

IsScriptEnabled is whether pages run JavaScript, true by default. A change applies from the next navigation; ExecuteScript runs scripts either way.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
if pWebView2->IsScriptEnabled then pWebView2->IsScriptEnabled( false )

Microsoft Learn: ICoreWebView2Settings::put_IsScriptEnabled

IsWebMessageEnabled

property IsWebMessageEnabled() as boolean
property IsWebMessageEnabled( byval enabled as boolean ) as HRESULT

Whether messages pass between the program and the page in both directions (PostWebMessageAsJson and window.chrome.webview.postMessage), true by default. A change applies from the next navigation.

Example

CWebView2Ptr( hwnd )->IsWebMessageEnabled( true )

Microsoft Learn: ICoreWebView2Settings::put_IsWebMessageEnabled

AreDefaultScriptDialogsEnabled

property AreDefaultScriptDialogsEnabled() as boolean
property AreDefaultScriptDialogsEnabled( byval enabled as boolean ) as HRESULT

Whether alert, confirm, prompt and beforeunload show the browser's own dialogs, true by default. With false, nothing is shown and the program answers them in a ScriptDialogOpening handler.

Example

CWebView2Ptr( hwnd )->AreDefaultScriptDialogsEnabled( false )

Microsoft Learn: ICoreWebView2Settings::put_AreDefaultScriptDialogsEnabled

IsStatusBarEnabled

property IsStatusBarEnabled() as boolean
property IsStatusBarEnabled( byval enabled as boolean ) as HRESULT

Whether the address of a link under the mouse shows in a small bar at the bottom left, true by default.

Example

CWebView2Ptr( hwnd )->IsStatusBarEnabled( false )

Microsoft Learn: ICoreWebView2Settings::put_IsStatusBarEnabled

AreDevToolsEnabled

property AreDevToolsEnabled() as boolean
property AreDevToolsEnabled( byval enabled as boolean ) as HRESULT

Whether the user can open the developer tools with F12, Ctrl+Shift+I or the context menu, true by default. OpenDevToolsWindow works either way.

Example

CWebView2Ptr( hwnd )->AreDevToolsEnabled( false )

Microsoft Learn: ICoreWebView2Settings::put_AreDevToolsEnabled

AreDefaultContextMenusEnabled

property AreDefaultContextMenusEnabled() as boolean
property AreDefaultContextMenusEnabled( byval enabled as boolean ) as HRESULT

Whether right-clicking shows the browser's context menu, true by default.

Example

CWebView2Ptr( hwnd )->AreDefaultContextMenusEnabled( false )

Microsoft Learn: ICoreWebView2Settings::put_AreDefaultContextMenusEnabled

AreHostObjectsAllowed

property AreHostObjectsAllowed() as boolean
property AreHostObjectsAllowed( byval allowed as boolean ) as HRESULT

Whether pages can reach the objects of AddHostObjectToScript, true by default.

Example

CWebView2Ptr( hwnd )->AreHostObjectsAllowed( false )

Microsoft Learn: ICoreWebView2Settings::put_AreHostObjectsAllowed

IsZoomControlEnabled

property IsZoomControlEnabled() as boolean
property IsZoomControlEnabled( byval allowed as boolean ) as HRESULT

Whether the user can zoom with Ctrl and the mouse wheel or Ctrl with + and -, true by default. SetZoomFactor works either way.

Example

CWebView2Ptr( hwnd )->IsZoomControlEnabled( false )

Microsoft Learn: ICoreWebView2Settings::put_IsZoomControlEnabled

IsBuiltInErrorPageEnabled

property IsBuiltInErrorPageEnabled() as boolean
property IsBuiltInErrorPageEnabled( byval allowed as boolean ) as HRESULT

Whether a failed navigation, or a crashed page, shows the browser's error page, true by default. With false the page stays blank and the program can show its own.

Example

CWebView2Ptr( hwnd )->IsBuiltInErrorPageEnabled( false )

Microsoft Learn: ICoreWebView2Settings::put_IsBuiltInErrorPageEnabled

AddNavigationStarting, RemoveNavigationStarting

function AddNavigationStarting( byval eventHandler as ICoreWebView2NavigationStartingEventHandler ptr, byval token as EventRegistrationToken ptr ) as HRESULT
function RemoveNavigationStarting( byval token as EventRegistrationToken ) as HRESULT

The event methods all work the same way. Add… registers a handler object and fills token, which Remove… takes to unregister it. The handler is an object of a type derived from the matching class of WebView2 event handlers, with its Invoke written for the program, created with new and passed as cast( any ptr, p ); the WebView keeps a reference to it and the object deletes itself when that is released. Several handlers can be registered for one event. The snippets pass the base classes, whose Invoke does nothing. These methods do not check for a browser: each needs a ready WebView.

Returns the HRESULT.

NavigationStarting is raised before each top-level navigation; the handler can read the URL and cancel it.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
dim token as EventRegistrationToken
pWebView2->AddNavigationStarting( cast( any ptr, new CWebView2NavigationStartingdEventHandler ), @token )
pWebView2->RemoveNavigationStarting( token )

Microsoft Learn: ICoreWebView2::add_NavigationStarting

AddNavigationCompleted, RemoveNavigationCompleted

function AddNavigationCompleted( byval eventHandler as ICoreWebView2NavigationCompletedEventHandler ptr, byval token as EventRegistrationToken ptr ) as HRESULT
function RemoveNavigationCompleted( byval token as EventRegistrationToken ) as HRESULT

NavigationCompleted is raised when a top-level document has loaded, or failed to: the arguments tell whether it succeeded and, if not, why.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
dim token as EventRegistrationToken
pWebView2->AddNavigationCompleted( cast( any ptr, new CWebView2NavigationCompletedEventHandler ), @token )
pWebView2->RemoveNavigationCompleted( token )

Microsoft Learn: ICoreWebView2::add_NavigationCompleted

AddFrameNavigationStarting, RemoveFrameNavigationStarting

function AddFrameNavigationStarting( byval eventHandler as ICoreWebView2NavigationStartingEventHandler ptr, byval token as EventRegistrationToken ptr ) as HRESULT
function RemoveFrameNavigationStarting( byval token as EventRegistrationToken ) as HRESULT

FrameNavigationStarting is NavigationStarting for a navigation inside a frame (<iframe>); it takes the same kind of handler.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
dim token as EventRegistrationToken
pWebView2->AddFrameNavigationStarting( cast( any ptr, new CWebView2NavigationStartingdEventHandler ), @token )
pWebView2->RemoveFrameNavigationStarting( token )

Microsoft Learn: ICoreWebView2::add_FrameNavigationStarting

AddFrameNavigationCompleted, RemoveFrameNavigationCompleted

function AddFrameNavigationCompleted( byval eventHandler as ICoreWebView2NavigationCompletedEventHandler ptr, byval token as EventRegistrationToken ptr ) as HRESULT
function RemoveFrameNavigationCompleted( byval token as EventRegistrationToken ) as HRESULT

FrameNavigationCompleted is NavigationCompleted for a frame; it takes the same kind of handler.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
dim token as EventRegistrationToken
pWebView2->AddFrameNavigationCompleted( cast( any ptr, new CWebView2NavigationCompletedEventHandler ), @token )
pWebView2->RemoveFrameNavigationCompleted( token )

Microsoft Learn: ICoreWebView2::add_FrameNavigationCompleted

AddContentLoading, RemoveContentLoading

function AddContentLoading( byval eventHandler as ICoreWebView2ContentLoadingEventHandler ptr, byval token as EventRegistrationToken ptr ) as HRESULT
function RemoveContentLoading( byval token as EventRegistrationToken ) as HRESULT

ContentLoading is raised when the new document starts loading, before any of its content has been shown.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
dim token as EventRegistrationToken
pWebView2->AddContentLoading( cast( any ptr, new CWebView2ContentLoadingEventHandler ), @token )
pWebView2->RemoveContentLoading( token )

Microsoft Learn: ICoreWebView2::add_ContentLoading

AddSourceChanged, RemoveSourceChanged

function AddSourceChanged( byval eventHandler as ICoreWebView2SourceChangedEventHandler ptr, byval token as EventRegistrationToken ptr ) as HRESULT
function RemoveSourceChanged( byval token as EventRegistrationToken ) as HRESULT

SourceChanged is raised when the URL of the top-level document changes, including a jump to an anchor in the same page; GetSource returns the new one. An address bar is kept up to date from it.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
dim token as EventRegistrationToken
pWebView2->AddSourceChanged( cast( any ptr, new CWebView2SourceChangedEventHandler ), @token )
pWebView2->RemoveSourceChanged( token )

Microsoft Learn: ICoreWebView2::add_SourceChanged

AddHistoryChanged, RemoveHistoryChanged

function AddHistoryChanged( byval eventHandler as ICoreWebView2SourceChangedEventHandler ptr, byval token as EventRegistrationToken ptr ) as HRESULT
function RemoveHistoryChanged( byval token as EventRegistrationToken ) as HRESULT

These two register and unregister a handler for the SourceChanged event, exactly as AddSourceChanged and RemoveSourceChanged do, and their handler type is the SourceChanged one. The HistoryChanged event itself, raised when the history changes (which is when CanGoBack and CanGoForward may have changed), is registered on the raw interface: GetWebViewPtr()->add_HistoryChanged( … ).

Example

dim pCore as ICoreWebView2 ptr = CWebView2Ptr( hwnd )->GetWebViewPtr()
dim token as EventRegistrationToken
pCore->add_HistoryChanged( cast( any ptr, new CWebView2HistoryChangedEventHandler ), @token )
pCore->remove_HistoryChanged( token )

Microsoft Learn: ICoreWebView2::add_HistoryChanged

AddScriptDialogOpening, RemoveScriptDialogOpening

function AddScriptDialogOpening( byval eventHandler as ICoreWebView2ScriptDialogOpeningEventHandler ptr, byval token as EventRegistrationToken ptr ) as HRESULT
function RemoveScriptDialogOpening( byval token as EventRegistrationToken ) as HRESULT

ScriptDialogOpening is raised when the page calls alert, confirm or prompt, or asks before unloading, and AreDefaultScriptDialogsEnabled is false; the handler shows a dialog of its own and gives the answer.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
dim token as EventRegistrationToken
pWebView2->AddScriptDialogOpening( cast( any ptr, new CWebView2ScriptDialogOpeningEventHandler ), @token )
pWebView2->RemoveScriptDialogOpening( token )

Microsoft Learn: ICoreWebView2::add_ScriptDialogOpening

AddPermissionRequested, RemovePermissionRequested

function AddPermissionRequested( byval eventHandler as ICoreWebView2PermissionRequestedEventHandler ptr, byval token as EventRegistrationToken ptr ) as HRESULT
function RemovePermissionRequested( byval token as EventRegistrationToken ) as HRESULT

PermissionRequested is raised when a page asks for the microphone, camera, location, notifications, the clipboard and so on; the handler allows or denies it, or leaves the browser to ask the user.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
dim token as EventRegistrationToken
pWebView2->AddPermissionRequested( cast( any ptr, new CWebView2PermissionRequestedEventHandler ), @token )
pWebView2->RemovePermissionRequested( token )

Microsoft Learn: ICoreWebView2::add_PermissionRequested

AddProcessFailed, RemoveProcessFailed

function AddProcessFailed( byval eventHandler as ICoreWebView2ProcessFailedEventHandler ptr, byval token as EventRegistrationToken ptr ) as HRESULT
function RemoveProcessFailed( byval token as EventRegistrationToken ) as HRESULT

ProcessFailed is raised when one of the browser's processes crashes, hangs or ends; the arguments say which kind. When the browser process itself has gone, the program must create a new CWebView2.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
dim token as EventRegistrationToken
pWebView2->AddProcessFailed( cast( any ptr, new CWebView2ProcessFailedEventHandler ), @token )
pWebView2->RemoveProcessFailed( token )

Microsoft Learn: ICoreWebView2::add_ProcessFailed

AddWebMessageReceived, RemoveWebMessageReceived

function AddWebMessageReceived( byval eventHandler as ICoreWebView2WebMessageReceivedEventHandler ptr, byval token as EventRegistrationToken ptr ) as HRESULT
function RemoveWebMessageReceived( byval token as EventRegistrationToken ) as HRESULT

WebMessageReceived is raised when the top-level document calls window.chrome.webview.postMessage( value ); the handler reads the value as a string or as JSON, as the Example does. Needs IsWebMessageEnabled.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
dim token as EventRegistrationToken
pWebView2->AddWebMessageReceived( cast( any ptr, new CWebView2WebMessageReceivedEventHandler ), @token )
pWebView2->RemoveWebMessageReceived( token )

Microsoft Learn: ICoreWebView2::add_WebMessageReceived

AddNewWindowRequested, RemoveNewWindowRequested

function AddNewWindowRequested( byval eventHandler as ICoreWebView2NewWindowRequestedEventHandler ptr, byval token as EventRegistrationToken ptr ) as HRESULT
function RemoveNewWindowRequested( byval token as EventRegistrationToken ) as HRESULT

NewWindowRequested is raised when the page opens a new window: window.open, a link with target="_blank", or the user's "open in new window". Unhandled, the browser opens its own pop-up window. CWebView2NewWindowRequestedEventHandlerInternal is a ready-made handler that loads the page in the same browser instead.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
dim token as EventRegistrationToken
pWebView2->AddNewWindowRequested( cast( any ptr, new CWebView2NewWindowRequestedEventHandler ), @token )
pWebView2->RemoveNewWindowRequested( token )

Microsoft Learn: ICoreWebView2::add_NewWindowRequested

AddDocumentTitleChanged, RemoveDocumentTitleChanged

function AddDocumentTitleChanged( byval eventHandler as ICoreWebView2DocumentTitleChangedEventHandler ptr, byval token as EventRegistrationToken ptr ) as HRESULT
function RemoveDocumentTitleChanged( byval token as EventRegistrationToken ) as HRESULT

DocumentTitleChanged is raised when the title of the top-level document changes; the handler reads it with the sender's get_DocumentTitle, for instance to put it in the caption.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
dim token as EventRegistrationToken
pWebView2->AddDocumentTitleChanged( cast( any ptr, new CWebView2DocumentTitleChangedEventHandler ), @token )
pWebView2->RemoveDocumentTitleChanged( token )

Microsoft Learn: ICoreWebView2::add_DocumentTitleChanged

AddContainsFullScreenElementChanged, RemoveContainsFullScreenElementChanged

function AddContainsFullScreenElementChanged( byval eventHandler as ICoreWebView2ContainsFullScreenElementChangedEventHandler ptr, byval token as EventRegistrationToken ptr ) as HRESULT
function RemoveContainsFullScreenElementChanged( byval token as EventRegistrationToken ) as HRESULT

ContainsFullScreenElementChanged is raised when an element of the page enters or leaves full screen; GetContainsFullScreenElement says which.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
dim token as EventRegistrationToken
pWebView2->AddContainsFullScreenElementChanged( cast( any ptr, new CWebView2ContainsFullScreenElementChangedEventHandler ), @token )
pWebView2->RemoveContainsFullScreenElementChanged( token )

Microsoft Learn: ICoreWebView2::add_ContainsFullScreenElementChanged

AddWebResourceRequested, RemoveWebResourceRequested

function AddWebResourceRequested( byval eventHandler as ICoreWebView2WebResourceRequestedEventHandler ptr, byval token as EventRegistrationToken ptr ) as HRESULT
function RemoveWebResourceRequested( byval token as EventRegistrationToken ) as HRESULT

WebResourceRequested is raised for each request that matches a filter of AddWebResourceRequestedFilter; the handler can read the request, change it, or give the response itself.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
dim token as EventRegistrationToken
pWebView2->AddWebResourceRequested( cast( any ptr, new CWebView2WebResourceRequestedEventHandler ), @token )
pWebView2->RemoveWebResourceRequested( token )

Microsoft Learn: ICoreWebView2::add_WebResourceRequested

AddWindowCloseRequested, RemoveWindowCloseRequested

function AddWindowCloseRequested( byval eventHandler as ICoreWebView2WindowCloseRequestedEventHandler ptr, byval token as EventRegistrationToken ptr ) as HRESULT
function RemoveWindowCloseRequested( byval token as EventRegistrationToken ) as HRESULT

WindowCloseRequested is raised when the page calls window.close(); the browser does not close by itself, so the handler closes it or its window.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
dim token as EventRegistrationToken
pWebView2->AddWindowCloseRequested( cast( any ptr, new CWebView2WindowCloseRequestedEventHandler ), @token )
pWebView2->RemoveWindowCloseRequested( token )

Microsoft Learn: ICoreWebView2::add_WindowCloseRequested

AddZoomFactorChanged, RemoveZoomFactorChanged

function AddZoomFactorChanged( byval eventHandler as ICoreWebView2ZoomFactorChangedEventHandler ptr, byval token as EventRegistrationToken ptr ) as HRESULT
function RemoveZoomFactorChanged( byval token as EventRegistrationToken ) as HRESULT

ZoomFactorChanged is raised when the zoom changes, by the user or by SetZoomFactor. This event and the four below belong to the controller: their handler's Invoke receives an ICoreWebView2Controller as the sender.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
dim token as EventRegistrationToken
pWebView2->AddZoomFactorChanged( cast( any ptr, new CWebView2ZoomFactorChangedEventHandler ), @token )
pWebView2->RemoveZoomFactorChanged( token )

Microsoft Learn: ICoreWebView2Controller::add_ZoomFactorChanged

AddMoveFocusRequested, RemoveMoveFocusRequested

function AddMoveFocusRequested( byval eventHandler as ICoreWebView2MoveFocusRequestedEventHandler ptr, byval token as EventRegistrationToken ptr ) as HRESULT
function RemoveMoveFocusRequested( byval token as EventRegistrationToken ) as HRESULT

MoveFocusRequested is raised when Tab or Shift+Tab would take the focus out of the page; the handler moves it to the next control of the window.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
dim token as EventRegistrationToken
pWebView2->AddMoveFocusRequested( cast( any ptr, new CWebView2MoveFocusRequestedEventHandler ), @token )
pWebView2->RemoveMoveFocusRequested( token )

Microsoft Learn: ICoreWebView2Controller::add_MoveFocusRequested

AddGotFocus, RemoveGotFocus

function AddGotFocus( byval eventHandler as ICoreWebView2FocusChangedEventHandler ptr, byval token as EventRegistrationToken ptr ) as HRESULT
function RemoveGotFocus( byval token as EventRegistrationToken ) as HRESULT

GotFocus is raised when the browser gets the keyboard focus.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
dim token as EventRegistrationToken
pWebView2->AddGotFocus( cast( any ptr, new CWebView2FocusChangedEventHandler ), @token )
pWebView2->RemoveGotFocus( token )

Microsoft Learn: ICoreWebView2Controller::add_GotFocus

AddLostFocus, RemoveLostFocus

function AddLostFocus( byval eventHandler as ICoreWebView2FocusChangedEventHandler ptr, byval token as EventRegistrationToken ptr ) as HRESULT
function RemoveLostFocus( byval token as EventRegistrationToken ) as HRESULT

LostFocus is raised when the browser loses the keyboard focus.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
dim token as EventRegistrationToken
pWebView2->AddLostFocus( cast( any ptr, new CWebView2FocusChangedEventHandler ), @token )
pWebView2->RemoveLostFocus( token )

Microsoft Learn: ICoreWebView2Controller::add_LostFocus

AddAcceleratorKeyPressed, RemoveAcceleratorKeyPressed

function AddAcceleratorKeyPressed( byval eventHandler as ICoreWebView2AcceleratorKeyPressedEventHandler ptr, byval token as EventRegistrationToken ptr ) as HRESULT
function RemoveAcceleratorKeyPressed( byval token as EventRegistrationToken ) as HRESULT

AcceleratorKeyPressed is raised, while the browser has the focus, for keys and combinations the host may want for itself: function keys, Ctrl or Alt combinations, Esc and so on. The handler can act on the key and mark it handled so that the page never sees it.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
dim token as EventRegistrationToken
pWebView2->AddAcceleratorKeyPressed( cast( any ptr, new CWebView2AcceleratorKeyPressedEventHandler ), @token )
pWebView2->RemoveAcceleratorKeyPressed( token )

Microsoft Learn: ICoreWebView2Controller::add_AcceleratorKeyPressed

Related functions

Function	Does
CWebView2Ptr	Returns the `CWebView2` that a host window holds.
SaveTempHtmlFile	Saves HTML as a UTF-8 file in the temporary folder.
CreateCoreWebView2Environment	Starts creating an environment with the default runtime and profile.
CreateCoreWebView2EnvironmentWithOptions	Starts creating an environment with a chosen runtime, profile and options.
CreateCoreWebView2EnvironmentWithDetails	The older form, with browser arguments as a string.
GetAvailableCoreWebView2BrowserVersionString	Returns the version of the runtime that would be used.
CompareBrowserVersions	Compares two version strings.

The five functions that create environments or read versions are those of WebView2Loader.dll: each loads the DLL, calls its function of the same name and frees the DLL again, and returns E_POINTER when the DLL or the function cannot be found.

CWebView2Ptr

function CWebView2Ptr( byval hWin as HWND ) as CWebView2 ptr

Returns the CWebView2 whose address the constructor (or SetParentWindow) stored in hWin's GWLP_USERDATA slot, so that a window procedure needs no global. Pass the window that hosts the browser: for one created in a control, that control. It returns whatever the slot holds, so it is only meaningful for a host window.

Returns the object, or NULL when hWin is not a window or holds no address yet. It is a plain pointer: nothing to release.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
if pWebView2 then pWebView2->Reload()

SaveTempHtmlFile

function SaveTempHtmlFile( byval pwszBuffer as wstring ptr ) as ustring

Writes the text in pwszBuffer to a new file in the user's temporary folder, as UTF-8 with a byte-order mark and a carriage return and line feed added at the end, and gives it the extension .html (TMP2D4A.html). Use it for pages too large for NavigateToString, or whose relative links and scripts must load: navigate to "file:///" & name. The program deletes the file when done.

Returns the full path of the file; the .tmp name it was created with when the rename failed; "" when it could not be created.

Example

dim ustrFile as ustring = SaveTempHtmlFile( "<h1>Report</h1>" )
CWebView2Ptr( hwnd )->Navigate( "file:///" & ustrFile )

Microsoft Learn: GetTempFileNameW

CreateCoreWebView2Environment

function CreateCoreWebView2Environment( byval environment_created_handler as ICoreWebView2CreateCoreWebView2EnvironmentCompletedHandler ptr ) as HRESULT

Starts creating an environment with the installed runtime and the default profile folder, as CreateCoreWebView2EnvironmentWithOptions does with NULL for everything. The environment arrives later, in the handler's Invoke. The CWebView2 constructor calls it without a profile folder; call it yourself to build the browser step by step.

Parameter	Meaning
`environment_created_handler`	An object derived from `CWebView2CreateCoreWebView2EnvironmentCompletedHandler`, passed as `cast( any ptr, p )`.

Returns S_OK when creation started; E_POINTER without the loader DLL; otherwise the loader's error.

Example

dim pHandler as CWebView2CreateCoreWebView2EnvironmentCompletedHandler ptr = new CWebView2CreateCoreWebView2EnvironmentCompletedHandler
if CreateCoreWebView2Environment( cast( any ptr, pHandler ) ) <> S_OK then print "no loader"

Microsoft Learn: CreateCoreWebView2Environment

CreateCoreWebView2EnvironmentWithOptions

function CreateCoreWebView2EnvironmentWithOptions( byval browserExecutableFolder as PCWSTR, byval userDataFolder as PCWSTR, byval environmentOptions as ICoreWebView2EnvironmentOptions ptr, byval environment_created_handler as ICoreWebView2CreateCoreWebView2EnvironmentCompletedHandler ptr ) as HRESULT

Starts creating an environment, choosing the runtime, the profile folder and the options.

Parameter	Meaning
`browserExecutableFolder`	A folder holding a fixed-version runtime shipped with the program, or `NULL` for the installed one.
`userDataFolder`	The profile folder, or `NULL` for `<program>.exe.WebView2` next to the program.
`environmentOptions`	An object implementing `ICoreWebView2EnvironmentOptions` (browser arguments, language, …), or `NULL`.
`environment_created_handler`	The handler that receives the environment, passed as `cast( any ptr, p )`.

The runtime also reads overrides from environment variables such as WEBVIEW2_USER_DATA_FOLDER and WEBVIEW2_ADDITIONAL_BROWSER_ARGUMENTS. A second environment in the same process must use the same folder and options as the first, or creation fails.

Returns S_OK when creation started; E_POINTER without the loader DLL; otherwise the loader's error.

Example

dim pHandler as CWebView2CreateCoreWebView2EnvironmentCompletedHandler ptr = new CWebView2CreateCoreWebView2EnvironmentCompletedHandler
CreateCoreWebView2EnvironmentWithOptions( NULL, GetTempPath() & "MyAppWebView2", NULL, cast( any ptr, pHandler ) )

Microsoft Learn: CreateCoreWebView2EnvironmentWithOptions

CreateCoreWebView2EnvironmentWithDetails

function CreateCoreWebView2EnvironmentWithDetails( byval browserExecutableFolder as PCWSTR, byval userDataFolder as PCWSTR, byval additionalBrowserArguments as PCWSTR, byval environment_created_handler as ICoreWebView2CreateCoreWebView2EnvironmentCompletedHandler ptr ) as HRESULT

The early form of CreateCoreWebView2EnvironmentWithOptions, with the browser's command-line switches as a string. The loader has dropped it: the WebView2Loader.dll the toolchain ships does not export it, so with that DLL it always returns E_POINTER. Use …WithOptions.

Returns S_OK when creation started; E_POINTER without the loader DLL or the function.

Example

dim pHandler as CWebView2CreateCoreWebView2EnvironmentCompletedHandler ptr = new CWebView2CreateCoreWebView2EnvironmentCompletedHandler
if CreateCoreWebView2EnvironmentWithDetails( NULL, NULL, "--disable-gpu", cast( any ptr, pHandler ) ) = E_POINTER then print "not available"

GetAvailableCoreWebView2BrowserVersionString

function GetAvailableCoreWebView2BrowserVersionString( byval browserExecutableFolder as PCWSTR, byval versionInfo as LPWSTR ptr ) as HRESULT

Finds the runtime that an environment would use, without creating anything, and returns its version: the installed one for a NULL folder, otherwise the fixed-version runtime in that folder. A channel name follows the number for a preview build of Edge (beta, dev, canary). Use it at start-up to tell the user the runtime is missing.

Parameter	Meaning
`browserExecutableFolder`	A fixed-version runtime folder, or `NULL`.
`versionInfo`	Receives the version text, which you free with `CoTaskMemFree`.

Returns S_OK with the version; E_POINTER without the loader DLL; otherwise the loader's error, such as when no runtime is installed. On a machine with the runtime installed the example printed WebView2 Runtime 156.0.4314.58.

Example

dim pVersion as LPWSTR
if GetAvailableCoreWebView2BrowserVersionString( NULL, @pVersion ) = S_OK andalso pVersion <> NULL then
    print "WebView2 Runtime "; *cast( wstring ptr, pVersion )
    CoTaskMemFree( pVersion )
end if

Microsoft Learn: GetAvailableCoreWebView2BrowserVersionString

CompareBrowserVersions

function CompareBrowserVersions( byval version1 as PCWSTR, byval version2 as PCWSTR, byval result as INT_ ptr ) as HRESULT

Compares two runtime version strings number by number, ignoring a channel name after them, so that a program can check that the installed runtime is new enough.

Parameter	Meaning
`version1`, `version2`	The versions, such as `120.0.2210.91`.
`result`	Receives -1 when `version1` is older, 0 when they are the same, 1 when it is newer.

Returns S_OK; E_INVALIDARG (&h80070057) when a string is not a version; E_POINTER without the loader DLL. "120.0.2210.91" against "119.0.2151.97" gives 1, the other way round -1, and "100.0.1.0" against "100.0.1.0 beta" 0.

Example

dim r as long
if CompareBrowserVersions( "120.0.2210.91", "119.0.2151.97", @r ) = S_OK then print r    ' 1

Microsoft Learn: CompareBrowserVersions

Related types

The module's own handlers. The two creation handlers are what the constructor uses; the other two are ready-made event handlers a program can create.

Type	Does
CWebView2NewWindowRequestedEventHandlerInternal	Loads pages that would open a new window in the same browser.
CWebView2WebMessageReceivedEventHandlerInternal	Turns the page message `image-ready` into a `WM_NOTIFY`.
CWebView2CreateCoreWebView2EnvironmentCompletedHandlerInternal	Receives the environment and asks for the controller.
CWebView2CreateCoreWebView2ControllerCompletedHandlerInternal	Receives the controller and shows the browser.

Each is created with new and is not deleted by the program: the runtime holds a reference to it, and its Release deletes it when the count falls back to 0.

CWebView2NewWindowRequestedEventHandlerInternal

type CWebView2NewWindowRequestedEventHandlerInternal extends CWebView2NewWindowRequestedEventHandler
    function Invoke( byval sender as ICoreWebView2 ptr, byval args as ICoreWebView2NewWindowRequestedEventArgs ptr ) as HRESULT
    constructor( byval pWebView2 as CWebView2 ptr, byval useNewWindow as boolean = false )
    destructor()
    m_pWebView2 as CWebView2 ptr
    m_token as EventRegistrationToken
    m_useNewWindow as boolean
    m_hParentWindow as HWND
end type

A NewWindowRequested handler that registers itself. While it is registered, a page that opens a new window (window.open, target="_blank") has that page loaded in the same browser instead: the request is marked handled and its URL navigated to.

Constructor

Registers the handler on pWebView2 with AddNewWindowRequested, keeping the token in m_token. pWebView2 must be ready; with NULL nothing is registered. With useNewWindow true the handler does nothing and the browser opens its own window as usual. m_hParentWindow is not used.

Parameter	Meaning
`pWebView2`	The browser to watch.
`useNewWindow`	`false` (the default) loads new windows in place; `true` leaves them alone.

Example

dim pHandler as CWebView2NewWindowRequestedEventHandlerInternal ptr
pHandler = new CWebView2NewWindowRequestedEventHandlerInternal( CWebView2Ptr( hwnd ) )

Destructor

Unregisters the handler with RemoveNewWindowRequested. It runs when the object deletes itself.

Example

dim pHandler as CWebView2NewWindowRequestedEventHandlerInternal ptr = new CWebView2NewWindowRequestedEventHandlerInternal( NULL )
pHandler->AddRef() : pHandler->Release()    ' the count falls to 0: the destructor runs

Invoke

Called by the browser for each request. With useNewWindow false it marks the request handled and navigates the sender to its URL.

Returns S_OK.

Example

dim pHandler as CWebView2NewWindowRequestedEventHandlerInternal ptr = new CWebView2NewWindowRequestedEventHandlerInternal( CWebView2Ptr( hwnd ), false )
if pHandler->m_useNewWindow = false then print "new windows open in place"

Microsoft Learn: ICoreWebView2NewWindowRequestedEventHandler

CWebView2WebMessageReceivedEventHandlerInternal

type CWebView2WebMessageReceivedEventHandlerInternal extends CWebView2WebMessageReceivedEventHandler
    virtual function Invoke( byval sender as ICoreWebView2 ptr, byval args as ICoreWebView2WebMessageReceivedEventArgs ptr ) as HRESULT
    constructor( byval pWebView2 as CWebView2 ptr )
    virtual destructor()
    refCount as ULONG = 0
    m_pWebView2 as CWebView2 ptr
    m_token as EventRegistrationToken
    m_hdr as NMHDR
end type

A WebMessageReceived handler that registers itself and passes one message on to the window procedure: when the page posts the string image-ready (window.chrome.webview.postMessage('image-ready'), for instance from an image's onload), it posts a WM_NOTIFY to the host's top-level window. Other messages are ignored.

Constructor

Registers the handler on pWebView2 with AddWebMessageReceived, keeping the token in m_token. pWebView2 must be ready; with NULL nothing is registered.

Example

dim pHandler as CWebView2WebMessageReceivedEventHandlerInternal ptr
pHandler = new CWebView2WebMessageReceivedEventHandlerInternal( CWebView2Ptr( hCtrl ) )

Destructor

Unregisters the handler with RemoveWebMessageReceived. It runs when the object deletes itself.

Example

dim pHandler as CWebView2WebMessageReceivedEventHandlerInternal ptr = new CWebView2WebMessageReceivedEventHandlerInternal( NULL )
pHandler->AddRef() : pHandler->Release()    ' the count falls to 0: the destructor runs

Invoke

Called by the browser for each message. It reads the message as a string; for image-ready it fills m_hdr and posts the notification described above.

Returns S_OK.

Example

function IsImageReady( byval wParam as WPARAM, byval lParam as LPARAM ) as boolean
    ' for WM_NOTIFY in the top-level window's procedure
    dim pnmh as NMHDR ptr = cast( NMHDR ptr, wParam )
    return pnmh->code = &hFFFFFFFF andalso CWebView2Ptr( pnmh->hwndFrom ) = cast( CWebView2 ptr, lParam )
end function

Microsoft Learn: WM_NOTIFY

CWebView2CreateCoreWebView2EnvironmentCompletedHandlerInternal

type CWebView2CreateCoreWebView2EnvironmentCompletedHandlerInternal extends object
    virtual function QueryInterface( byval riid as REFIID, byval ppvObject as LPVOID ptr ) as HRESULT
    virtual function AddRef() as ULONG
    virtual function Release() as ULONG
    virtual function Invoke( byval errorCode as HRESULT, byval createdEnvironment as ICoreWebView2Environment ptr ) as HRESULT
    constructor( byval pWebView2 as CWebView2 ptr )
    destructor()
    refCount as ULONG = 0
    m_pWebView2 as CWebView2 ptr
end type

The handler the constructor passes when it asks for the environment. Its virtual members are in the order of the COM interface it stands for.

Constructor, Destructor

The constructor stores pWebView2, the object to fill; the destructor does nothing.

Example

dim pHandler as CWebView2CreateCoreWebView2EnvironmentCompletedHandlerInternal ptr
pHandler = new CWebView2CreateCoreWebView2EnvironmentCompletedHandlerInternal( CWebView2Ptr( hwnd ) )
CreateCoreWebView2Environment( cast( any ptr, pHandler ) )

QueryInterface, AddRef, Release

AddRef and Release count references from 0; Release deletes the object when the count gets back to 0. QueryInterface returns S_OK for any interface and leaves ppvObject as it is.

Returns AddRef and Release: the new count. QueryInterface: S_OK.

Example

dim pHandler as CWebView2CreateCoreWebView2EnvironmentCompletedHandlerInternal ptr = new CWebView2CreateCoreWebView2EnvironmentCompletedHandlerInternal( NULL )
print pHandler->AddRef()     ' 1
print pHandler->Release()    ' 0, and the object is gone

Invoke

Called by the runtime with the result. On success it keeps the environment in the CWebView2 (adding a reference), asks it for a controller in the host window with a CWebView2CreateCoreWebView2ControllerCompletedHandlerInternal, and stores the runtime's version for GetBrowserVersion. On failure it does nothing: the error is not stored, and IsReady never sees a controller.

Returns S_OK.

Example

dim pHandler as CWebView2CreateCoreWebView2EnvironmentCompletedHandlerInternal ptr = new CWebView2CreateCoreWebView2EnvironmentCompletedHandlerInternal( NULL )
pHandler->Invoke( E_FAIL, NULL )     ' a failed creation: nothing happens

Microsoft Learn: ICoreWebView2CreateCoreWebView2EnvironmentCompletedHandler

CWebView2CreateCoreWebView2ControllerCompletedHandlerInternal

type CWebView2CreateCoreWebView2ControllerCompletedHandlerInternal extends object
    virtual function QueryInterface( byval riid as REFIID, byval ppvObject as LPVOID ptr ) as HRESULT
    virtual function AddRef() as ULONG
    virtual function Release() as ULONG
    virtual function Invoke( byval errorCode as HRESULT, byval createdController as ICoreWebView2Controller ptr ) as HRESULT
    constructor( byval pWebView2 as CWebView2 ptr )
    destructor()
    refCount as ULONG = 0
    m_pWebView2 as CWebView2 ptr
end type

The handler the environment handler passes when it asks for the controller.

Constructor, Destructor

The constructor stores pWebView2, the object to fill; the destructor does nothing.

Example

dim pWebView2 as CWebView2 ptr = CWebView2Ptr( hwnd )
dim pHandler as CWebView2CreateCoreWebView2ControllerCompletedHandlerInternal ptr = new CWebView2CreateCoreWebView2ControllerCompletedHandlerInternal( pWebView2 )
pWebView2->GetEnvironmentPtr()->CreateCoreWebView2Controller( hwnd, cast( any ptr, pHandler ) )

QueryInterface, AddRef, Release

As for the environment handler: a count from 0, deletion at 0, and a QueryInterface that returns S_OK without filling ppvObject.

Returns AddRef and Release: the new count. QueryInterface: S_OK.

Example

dim pHandler as CWebView2CreateCoreWebView2ControllerCompletedHandlerInternal ptr = new CWebView2CreateCoreWebView2ControllerCompletedHandlerInternal( NULL )
print pHandler->AddRef()     ' 1
print pHandler->Release()    ' 0, and the object is gone

Invoke

Called by the runtime with the result. On success it keeps the controller in the CWebView2 (adding a reference) and its WebView, makes the browser visible and sizes it to the host's client area. That is the moment IsReady waits for. On failure it does nothing.

Returns S_OK.

Example

dim pHandler as CWebView2CreateCoreWebView2ControllerCompletedHandlerInternal ptr = new CWebView2CreateCoreWebView2ControllerCompletedHandlerInternal( NULL )
pHandler->Invoke( E_FAIL, NULL )     ' a failed creation: nothing happens

Microsoft Learn: ICoreWebView2CreateCoreWebView2ControllerCompletedHandler