See Also
 Important: |
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| This is retired content. This content is outdated and is no longer being maintained. It is provided as a courtesy for individuals who are still using these technologies. This content may contain URLs that were valid when originally published, but now link to sites or pages that no longer exist. |
This method specifies a window to which the video window will post messages.
Syntax
HRESULT put_MessageDrain( OAHWND Drain ); |
Parameters
- Drain
-
[in] Window to which messages will be posted.
Return Value
Returns an HRESULTvalue.
Remarks
The video renderer passes messages to the specified message drain by calling the Win32 PostMessagefunction.
These messages allow you to write applications that include user interaction, such as applications that require mouse clicks on specific areas of the video display.
An application can have a close relationship with the video window and know at certain time points to look for user interaction.
When the renderer passes a message to the drain, it sends the parameters, such as the client-area coordinates, exactly as generated.
DirectShow passes the following messages to the window specified by the Drainparameter, if and when the application generates them:
- WM_KEYDOWN
- WM_KEYUP
- WM_LBUTTONDBLCLK
- WM_LBUTTONDOWN
- WM_LBUTTONUP
- WM_MBUTTONDBLCLK
- WM_MBUTTONDOWN
- WM_MBUTTONUP
- WM_MOUSEACTIVATE
- WM_MOUSEMOVE
- WM_RBUTTONDBLCLK
- WM_RBUTTONDOWN
- WM_RBUTTONUP
Because this member function does not make the message drain window a child window, applications with full-screen capabilities can use it.
Requirements
| Windows Embedded CE | Windows CE 2.12 and later |
| Windows Mobile | Pocket PC for Windows Mobile Version 5.0 and later, Smartphone for Windows Mobile Version 5.0 and later |
| Note | Microsoft DirectShow applications and DirectShow filters have
different include file and Library requirements
For more information, see Setting Up the Build Environment,Version 2.12 requires DXPAK 1.0 or later |