WM_COPYDATA message
Applies to: desktop apps only
An application sends the WM_COPYDATA message to pass data to another application.
#define WM_COPYDATA 0x004A
Parameters
- wParam
-
A handle to the window passing the data.
- lParam
-
A pointer to a COPYDATASTRUCT structure that contains the data to be passed.
Return value
If the receiving application processes this message, it should return TRUE; otherwise, it should return FALSE.
Remarks
The data being passed must not contain pointers or other references to objects not accessible to the application receiving the data.
While this message is being sent, the referenced data must not be changed by another thread of the sending process.
The receiving application should consider the data read-only. The lParam parameter is valid only during the processing of the message. The receiving application should not free the memory referenced by lParam. If the receiving application must access the data after SendMessage returns, it must copy the data into a local buffer.
Examples
For an example, see Using Data Copy.
Requirements
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Minimum supported client | Windows 2000 Professional |
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Minimum supported server | Windows 2000 Server |
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Header |
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See also
- Reference
- SendMessage
- COPYDATASTRUCT
Send comments about this topic to Microsoft
Build date: 3/6/2012
Check [url=http://msdn.microsoft.com/en-us/library/ms632675%28v=vs.85%29.aspx]ChangeWindowMessageFilter Function[/url] for more information regarding UIPI and how to unblock WM_COPYDATA or similar messages.
- 12/14/2010
- AhmedZaki
