CMFCDesktopAlertWnd Class

Article
07/22/2011

The CMFCDesktopAlertWnd class implements the functionality of a modeless dialog box which appears on the screen to inform the user about an event.

class CMFCDesktopAlertWnd : public CWnd

Members

Public Methods

Name	Description
CMFCDesktopAlertWnd::Create	Creates and initializes the desktop alert window.
CMFCDesktopAlertWnd::GetAnimationSpeed	Returns the animation speed.
CMFCDesktopAlertWnd::GetAnimationType	Returns the animation type.
CMFCDesktopAlertWnd::GetAutoCloseTime	Returns the auto-close time out.
CMFCDesktopAlertWnd::GetCaptionHeight	Returns the height of the caption.
CMFCDesktopAlertWnd::GetDialogSize
CMFCDesktopAlertWnd::GetLastPos	Returns the last valid position of the desktop alert window on the screen.
CMFCDesktopAlertWnd::GetTransparency	Returns the transparency level.
CMFCDesktopAlertWnd::HasSmallCaption	Determines whether the desktop alert window is displayed with the small caption.
CMFCDesktopAlertWnd::OnBeforeShow
CMFCDesktopAlertWnd::OnClickLinkButton	Called by the framework when the user clicks a link button located on the desktop alert menu.
CMFCDesktopAlertWnd::OnCommand	The framework calls this member function when the user selects an item from a menu, when a child control sends a notification message, or when an accelerator keystroke is translated. (Overrides CWnd::OnCommand.)
CMFCDesktopAlertWnd::OnDraw
CMFCDesktopAlertWnd::ProcessCommand
CMFCDesktopAlertWnd::SetAnimationSpeed	Sets the new animation speed.
CMFCDesktopAlertWnd::SetAnimationType	Sets the animation type.
CMFCDesktopAlertWnd::SetAutoCloseTime	Sets the auto-close time out.
CMFCDesktopAlertWnd::SetSmallCaption	Switches between small and normal captions.
CMFCDesktopAlertWnd::SetTransparency	Sets the transparency level.

Remarks

A desktop alert window can be transparent, it can appear with animation effects, and it can disappear (after a specified delay or when the user dismisses it by clicking the close button).

A desktop alert window can also contain a default dialog that in turn contains an icon, message text (a label), and a link. Alternatively, a desktop alert window can contain a custom dialog from the application's resources.

You create a desktop alert window in two steps. First, call the constructor to construct the CMFCDesktopAlertWnd object. Second, call the CMFCDesktopAlertWnd::Create member function to create the window and attach it to the CMFCDesktopAlertWnd object.

The CMFCDesktopAlertWnd object creates a special child dialog box that fills the client area of the desktop alert window. The dialog owns all the controls that are positioned on it.

To display a custom dialog box on the popup window, follow these steps:

Derive a class from CMFCDesktopAlertDialog.
Create a child dialog box template in the resources.
Call CMFCDesktopAlertWnd::Create using the resource ID of the dialog box template and a pointer to the runtime class information of the derived class.
Program the custom dialog box to handle all notifications coming from the hosted controls, or program the hosted controls to handle these notifications directly.

Use the following functions to control the behavior of the desktop alert window:

Set the animation type by calling CMFCDesktopAlertWnd::SetAnimationType. Valid options include unfold, slide, and fade.
Set the animation frame speed by calling CMFCDesktopAlertWnd::SetAnimationSpeed.
Set the transparency level by calling CMFCDesktopAlertWnd::SetTransparency.
Change the size of the caption to small by calling CMFCDesktopAlertWnd::SetSmallCaption. The small caption is 7 pixels high.

Example

The following example illustrates how to use various methods in the CMFCDesktopAlertWnd class to configure a CMFCDesktopAlertWnd object. The example shows how to set an animation type, set the transparency of the pop-up window, specify that the alert window displays a small caption, and set the time that elapses before the alert window automatically closes. The example also demonstrates how to create and initialize the desktop alert window. This code snippet is part of the Desktop Alert Demo sample.

    CMFCDesktopAlertWnd* pPopup = new CMFCDesktopAlertWnd;

    // int m_nAnimation
    pPopup->SetAnimationType ((CMFCPopupMenu::ANIMATION_TYPE) m_nAnimation);
    
    // int m_nAnimationSpeed
    pPopup->SetAnimationSpeed (m_nAnimationSpeed);
    
    // int m_nTransparency
    pPopup->SetTransparency ((BYTE)m_nTransparency);
    
    // BOOL m_bSmallCaption
    pPopup->SetSmallCaption (m_bSmallCaption);

    // BOOL m_bAutoClose, int m_nAutoCloseTime
    pPopup->SetAutoCloseTime (m_bAutoClose ? m_nAutoCloseTime * 1000 : 0);

    // int m_nPopupSource
    if (m_nPopupSource == 0)
    {
        // int m_nVisualMngr
        // CPoint m_ptPopup
        // The this pointer points to a CDesktopAlertDemoDlg class which extends the CDialogEx class.
        if (m_nVisualMngr == 5) // MSN-style
        {
            pPopup->Create (this, IDD_DIALOG2, NULL, 
                m_ptPopup, RUNTIME_CLASS (CMSNDlg));
        }
        else
        {
            pPopup->Create (this, IDD_DIALOG1, 
                m_menuPopup.GetSubMenu (0)->GetSafeHmenu (), 
                m_ptPopup, RUNTIME_CLASS (CMyPopupDlg));
        }
    }