How to use put_DefaultBackgroundColor correctly with WIn32?

[ajtruckle]

I know that we can set the background colour on demand like this:

void CWebBrowser::SetBackgroundColor(COLORREF colour, bool transparent)
{
	COREWEBVIEW2_COLOR webViewColour{};

	webViewColour.R = GetRValue(colour);
	webViewColour.G = GetGValue(colour);
	webViewColour.B = GetBValue(colour);
	webViewColour.A = transparent ? 0 : 255;
	wil::com_ptr<ICoreWebView2Controller2> controller2 =
		m_pImpl->m_webController.query<ICoreWebView2Controller2>();
	controller2->put_DefaultBackgroundColor(webViewColour);
}

And, I know that a recent update to WebView2 allows us to set the default background colour. ChatGPT suggests the following approach to using this new API:

#include <wrl.h>
#include <WebView2.h>

using namespace Microsoft::WRL;

void CreateWebView2WithCustomBackgroundColor(HWND hWnd)
{
    ComPtr<ICoreWebView2Environment> webViewEnvironment;

    // First, create the WebView2 environment
    HRESULT hr = CreateCoreWebView2EnvironmentWithOptions(
        nullptr, nullptr, nullptr,
        Callback<ICoreWebView2CreateCoreWebView2EnvironmentCompletedHandler>(
            [hWnd](HRESULT result, ICoreWebView2Environment* env) -> HRESULT
            {
                if (FAILED(result)) return result;

                ComPtr<ICoreWebView2Environment3> env3;
                if (SUCCEEDED(env->QueryInterface(IID_PPV_ARGS(&env3))))
                {
                    // Create controller options
                    ComPtr<ICoreWebView2ControllerOptions> options;
                    HRESULT hr = env3->CreateCoreWebView2ControllerOptions(&options);
                    if (FAILED(hr)) return hr;

                    // Set default background color via ICoreWebView2ControllerOptions3
                    ComPtr<ICoreWebView2ControllerOptions3> options3;
                    if (SUCCEEDED(options.As(&options3)))
                    {
                        COREWEBVIEW2_COLOR bgColor = { 255, 30, 30, 30 }; // A, R, G, B
                        options3->put_DefaultBackgroundColor(bgColor);
                    }

                    // Create controller with options
                    return env->CreateCoreWebView2ControllerWithOptions(
                        hWnd, options.Get(),
                        Callback<ICoreWebView2CreateCoreWebView2ControllerCompletedHandler>(
                            [](HRESULT result, ICoreWebView2Controller* controller) -> HRESULT
                            {
                                if (!controller) return result;

                                ComPtr<ICoreWebView2> webview;
                                controller->get_CoreWebView2(&webview);

                                // Your logic with webview here
                                return S_OK;
                            }).Get());
                }
                return E_NOINTERFACE;
            }).Get());
}

But I am not 100% sure that this is the right approach. So far, I have created the required environment in my EvenmentCompleted handler:

HRESULT CWebBrowser::OnCreateEnvironmentCompleted(
	HRESULT result,
	ICoreWebView2Environment* environment)
{
	CHECK_FAILURE(result);

	if (!environment)
		return E_FAIL;

	CHECK_FAILURE(environment->QueryInterface(IID_PPV_ARGS(&m_pImpl->m_webViewEnvironment)));
	CHECK_FAILURE(environment->QueryInterface(IID_PPV_ARGS(&m_pImpl->m_webViewEnvironment2)));
	CHECK_FAILURE(environment->QueryInterface(IID_PPV_ARGS(&m_pImpl->m_webViewEnvironment3)));

       // I need to add the correct code here to set the background.

	CHECK_FAILURE(m_pImpl->m_webViewEnvironment->CreateCoreWebView2Controller(
		m_hWnd,
		Callback<ICoreWebView2CreateCoreWebView2ControllerCompletedHandler>(
			this,
			&CWebBrowser::OnCreateWebViewControllerCompleted).Get()));

	return S_OK;
}

Where m_webViewEnvironment3 is defined as wil::com_ptr<ICoreWebView2Environment3> m_webViewEnvironment3;. But I can't see in the official sample an example of using the new API. Nor here . Sorry if I have overlooked a document explain this.

[ajtruckle]

I tried to insert the code snippet:

HRESULT CWebBrowser::OnCreateEnvironmentCompleted(
	HRESULT result,
	ICoreWebView2Environment* environment)
{
	CHECK_FAILURE(result);

	if (!environment)
		return E_FAIL;

	CHECK_FAILURE(environment->QueryInterface(IID_PPV_ARGS(&m_pImpl->m_webViewEnvironment)));
	CHECK_FAILURE(environment->QueryInterface(IID_PPV_ARGS(&m_pImpl->m_webViewEnvironment2)));
	CHECK_FAILURE(environment->QueryInterface(IID_PPV_ARGS(&m_pImpl->m_webViewEnvironment3)));

	ComPtr<ICoreWebView2ControllerOptions> options;
	HRESULT hr = m_pImpl->m_webViewEnvironment3->CreateCoreWebView2ControllerOptions(&options);
	if (FAILED(hr)) return hr;

	// Set default background color via ICoreWebView2ControllerOptions3
	ComPtr<ICoreWebView2ControllerOptions3> options3;
	if (SUCCEEDED(options.As(&options3)))
	{
		COREWEBVIEW2_COLOR bgColor = { 255, 30, 30, 30 }; // A, R, G, B
		options3->put_DefaultBackgroundColor(bgColor);
	}

	CHECK_FAILURE(m_pImpl->m_webViewEnvironment->CreateCoreWebView2Controller(
		m_hWnd,
		Callback<ICoreWebView2CreateCoreWebView2ControllerCompletedHandler>(
			this,
			&CWebBrowser::OnCreateWebViewControllerCompleted).Get()));

	return S_OK;
}

But it does not like this line:

HRESULT hr = m_pImpl->m_webViewEnvironment3->CreateCoreWebView2ControllerOptions(&options);

It says that CreateCoreWebView2ControllerOptions is undefined. Guidance appreciated. Thanks!

[ajtruckle]

Also tried:

	wil::com_ptr<ICoreWebView2ControllerOptions3> options3;
	CHECK_FAILURE(m_pImpl->m_webController->QueryInterface(IID_PPV_ARGS(&options3)));
	COREWEBVIEW2_COLOR bgColor = { 255, 30, 30, 30 }; // A, R, G, B
	CHECK_FAILURE(options3->put_DefaultBackgroundColor(bgColor));

but my program just shuts down.

[jls28]

the correct way is probably by using try_query<>(), in your case simply :
(assuming m_pImpl->m_webViewEnvironment is wil::com_ptr<ICoreWebView2Environment>)

auto webViewEnvironment10(m_pImpl->m_webViewEnvironment.try_query<ICoreWebView2Environment10>());
if (webViewEnvironment10)
{
wil::com_ptr<ICoreWebView2ControllerOptions> options;
webViewEnvironment10->CreateCoreWebView2ControllerOptions(&options);
...
auto options3(options.try_query<ICoreWebView2ControllerOptions3>());
if (options3)
  ....
}

[ajtruckle]

@jls28 I am sorry but this does not work.

	if (DarkModeTools::InvokeUseDarkModeFunction())
	{
		CHECK_FAILURE(environment->QueryInterface(IID_PPV_ARGS(&m_pImpl->m_webViewEnvironment3)));

		auto webViewEnvironment10(m_pImpl->m_webViewEnvironment.try_query<ICoreWebView2Environment10>());
		if (webViewEnvironment10)
		{
			wil::com_ptr<ICoreWebView2ControllerOptions> options;
			webViewEnvironment10->CreateCoreWebView2ControllerOptions(&options);
			auto options3(options.try_query<ICoreWebView2ControllerOptions3>());
			if (options3)
			{
				COREWEBVIEW2_COLOR bgColor = { 255, 
					GetRValue(DarkModeTools::kDarkBackgroundColor),
					GetGValue(DarkModeTools::kDarkBackgroundColor),
					GetBValue(DarkModeTools::kDarkBackgroundColor) }; // A, R, G, B
			}
		}
	}

options3 is null. Why isn't there a documented example?
@champnic

[jls28]

@ajtruckle

if webViewEnvironment10 is not null and options3 is null,
check your webview2 runtime version,

should be 137.0.3296.44 or higher
because
ICoreWebView2ControllerOptions3
require sdk 1.0.3296.44 (or or higher)
and this sdk require WebView2 Runtime version 137.0.3296.44 or higher.

[ajtruckle]

@jls28

• Runtime: 137.0.3296.68
• SDK: 3296.44

It is just options3 that seems to be null. Where did you get enironment10 from? I don't see it mentioned in the latest release notes.

[jls28]

see the documentation

ICoreWebView2Environment10 is required by CreateCoreWebView2ControllerOptions

in your code I see : m_webViewEnvironment3->CreateCoreWebView2ControllerOptions(&options)

this cannot compile because ICoreWebView2Environment3/ICoreWebView2Environment2/ICoreWebView2Environment1/ICoreWebView2Environment don't have a CreateCoreWebView2ControllerOptions function/method.

[ajtruckle]

When I run it in debug it does set the colour. I was running release so my breakpoint was bypassed. Sorry.

I have removed my references to environment3. But I would appreciate a url to the docs that say about environment 10.

[jls28]

https://learn.microsoft.com/en-us/microsoft-edge/webview2/reference/win32/icorewebview2environment10?view=webview2-1.0.3179.45

[ajtruckle]

See the related discussion. If I comment out the code in GetWindowClass so that it behaves like it did before, but keep this new code, I find that I still have a white flash. So I still need to keep this code:

PCTSTR CWebBrowser::GetWindowClass()
{
	static PCTSTR windowClass = []
	{
		static TCHAR const* className = L"EdgeBrowserHost";

		WNDCLASSEX wcex;
		wcex.cbSize = sizeof(WNDCLASSEX);

		wcex.style = CS_HREDRAW | CS_VREDRAW;
		wcex.lpfnWndProc = WndProcStatic;
		wcex.cbClsExtra = 0;
		wcex.cbWndExtra = 0;
		wcex.hInstance = AfxGetInstanceHandle();
		wcex.hIcon = nullptr;
		wcex.hCursor = LoadCursor(nullptr, IDC_ARROW);

		if (DarkModeTools::InvokeUseDarkModeFunction())
		{
			static auto hbr = CreateSolidBrush(DarkModeTools::kDarkBackgroundColor);
			wcex.hbrBackground = hbr;
		}
		else
			wcex.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);

		wcex.lpszMenuName = nullptr;
		wcex.lpszClassName = className;
		wcex.hIconSm = nullptr;

		ATOM result = RegisterClassEx(&wcex);
		if (result == 0)
		{
			[[maybe_unused]] DWORD lastError = ::GetLastError();
		}

		return className;
	}();

	return windowClass;
}

I was hoping that I would not need this wcex.hbrBackground code with the new api we are now using. Confused.