nf-uiribbon-iuiapplication-onviewchanged.md

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NF:uiribbon.IUIApplication.OnViewChanged	IUIApplication::OnViewChanged (uiribbon.h)	Called when the state of a View changes.	IUIApplication interface [Windows Ribbon] OnViewChanged method IUIApplication.OnViewChanged IUIApplication::OnViewChanged OnViewChanged OnViewChanged method [Windows Ribbon] OnViewChanged method [Windows Ribbon] IUIApplication interface scenicintent_IUIApplication_OnViewChanged uiribbon/IUIApplication::OnViewChanged windowsribbon.windowsribbon_iuiapplication_onviewchanged	windowsribbon\windowsribbon_iuiapplication_onviewchanged.htm	windowsribbon	VS|scenicintent|~\scenicintent\reference\ifaces\iuiapplication\onviewchanged.htm	12/05/2018	IUIApplication interface [Windows Ribbon],OnViewChanged method, IUIApplication.OnViewChanged, IUIApplication::OnViewChanged, OnViewChanged, OnViewChanged method [Windows Ribbon], OnViewChanged method [Windows Ribbon],IUIApplication interface, scenicintent_IUIApplication_OnViewChanged, uiribbon/IUIApplication::OnViewChanged, windowsribbon.windowsribbon_iuiapplication_onviewchanged	uiribbon.h		Windows	Windows 7 [desktop apps only]	Windows Server 2008 R2 [desktop apps only]					Uiribbon.idl						Mshtml.dll		Windows			Windows UI	19H1	IUIApplication::OnViewChanged uiribbon/IUIApplication::OnViewChanged	c++	APIRef kbSyntax	COM	Mshtml.dll	IUIApplication.OnViewChanged

IUIApplication::OnViewChanged

-description

Called when the state of a View changes.

-parameters

-param viewId [in]

Type: UINT32

The ID for the View. Only a value of 0 is valid.

-param typeID [in]

Type: UI_VIEWTYPE

The UI_VIEWTYPE hosted by the application.

-param view [in]

Type: IUnknown*

A pointer to the View interface.

-param verb [in]

Type: UI_VIEWVERB

The UI_VIEWVERB (or action) performed by the View.

-param uReasonCode [in]

Type: INT32

Not defined.

-returns

Type: HRESULT

If this method succeeds, it returns S_OK. Otherwise, it returns an HRESULT error code.

-remarks

This callback notification is sent by the framework to the host application on each View state change.

Important  This callback only occurs for the Ribbon View with a viewId of 0.

 

IUIApplication::OnViewChanged is useful for initializing Ribbon properties when the host application starts, modifying Ribbon properties based on user actions, such as resizing the application window, and querying Ribbon properties when the application closes.

Examples

The following example demonstrates a basic implementation of the IUIApplication::OnViewChanged method.

//
//  FUNCTION: OnViewChanged(UINT, UI_VIEWTYPE, IUnknown*, UI_VIEWVERB, INT)
//
//  PURPOSE: Called when the state of a View (Ribbon is a view) changes - like created/destroyed/resized.
//
//  PARAMETERS:    
//                viewId - The View identifier. 
//                typeID - The View type. 
//                pView - Pointer to the View interface. 
//                verb - The action performed by the View. 
//                uReasonCode - Not defined. 
//
//  COMMENTS:
//
//    For this sample, return the same command handler for all commands
//    specified in the .xml file.
//    
//
STDMETHODIMP CApplication::OnViewChanged(
    UINT viewId,
    UI_VIEWTYPE typeId,
    IUnknown* pView,
    UI_VIEWVERB verb,
    INT uReasonCode)
{
    HRESULT hr = E_NOTIMPL;
    
    // Checks to see if the view that was changed was a Ribbon view.
    if (UI_VIEWTYPE_RIBBON == typeId)
    {
        switch (verb)
        {            
            // The view was newly created.
            case UI_VIEWVERB_CREATE:
                _cwprintf(L"IUIApplication::OnViewChanged called with verb=CREATE\r\n");

                if (NULL == g_pRibbon)
                {
                    // Retrieve and store the IUIRibbon
                    hr = pView->QueryInterface(&g_pRibbon);
                }
                break;

            // The view was resized.  
            // In the case of the Ribbon view, the application should call 
            // GetHeight() to determine the height of the Ribbon.
            case UI_VIEWVERB_SIZE:
                _cwprintf(L"IUIApplication::OnViewChanged called with verb=SIZE\r\n");
                // Call to the framework to determine the height of the Ribbon.
                if (NULL != g_pRibbon)
                {
                    UINT uRibbonHeight;
                    hr = g_pRibbon->GetHeight(&uRibbonHeight);
                }
                if (!SUCCEEDED(hr))
                {
                    //_cwprintf(L"IUIRibbon::GetHeight() failed with hr=0x%X\r\n", hr);
                }
                break;
                
            // The view was destroyed.
            case UI_VIEWVERB_DESTROY:
                //_cwprintf(L"IUIApplication::OnViewChanged called with verb=DESTROY\r\n");
                g_pRibbon = NULL;
                hr = S_OK;
                break;
        }
    }
    return hr;
}

-see-also

IUIApplication

Windows Ribbon Framework Samples