The WTSSendMessage function displays a message box on the client desktop of a specified Remote Desktop Services session.

Syntax

BOOL WTSSendMessage(
  __in   HANDLE hServer,
  __in   DWORD SessionId,
  __in   LPTSTR pTitle,
  __in   DWORD TitleLength,
  __in   LPTSTR pMessage,
  __in   DWORD MessageLength,
  __in   DWORD Style,
  __in   DWORD Timeout,
  __out  DWORD *pResponse,
  __in   BOOL bWait
);

Parameters

hServer [in]

A handle to an RD Session Host server. Specify a handle opened by the WTSOpenServer function, or specify WTS_CURRENT_SERVER_HANDLE to indicate the RD Session Host server on which your application is running.

SessionId [in]

A Remote Desktop Services session identifier. To indicate the current session, specify WTS_CURRENT_SESSION. You can use the WTSEnumerateSessions function to retrieve the identifiers of all sessions on a specified RD Session Host server.

To send a message to another user's session, you need to have the Message permission. For more information, see Remote Desktop Services Services Permissions. To modify permissions on a session, use the Remote Desktop Services Configuration administrative tool.

pTitle [in]

A pointer to a null-terminated string for the title bar of the message box.

TitleLength [in]

The length, in bytes, of the title bar string.

pMessage [in]

A pointer to a null-terminated string that contains the message to display.

MessageLength [in]

The length, in bytes, of the message string.

Style [in]

The contents and behavior of the message box. This value is typically MB_OK. For a complete list of values, see the uType parameter of the MessageBox function.

Timeout [in]

The time, in seconds, that the WTSSendMessage function waits for the user's response. If the user does not respond within the time-out interval, the pResponse parameter returns IDTIMEOUT. If the Timeout parameter is zero, WTSSendMessage waits indefinitely for the user to respond.

pResponse [out]

A pointer to a variable that receives the user's response, which can be one of the following values.

Value	Meaning
IDABORT 3	Abort
IDCANCEL 2	Cancel
IDIGNORE 5	Ignore
IDNO 7	No
IDOK 1	OK
IDRETRY 4	Retry
IDYES 6	Yes
IDASYNC 32001 (0x7D01)	The bWait parameter was FALSE, so the function returned without waiting for a response.
IDTIMEOUT 32000 (0x7D00)	The bWait parameter was TRUE and the time-out interval elapsed.

 

bWait [in]

If TRUE, WTSSendMessage does not return until the user responds or the time-out interval elapses. If the Timeout parameter is zero, the function does not return until the user responds.

If FALSE, the function returns immediately and the pResponse parameter returns IDASYNC. Use this method for simple information messages (such as print job–notification messages) that do not need to return the user's response to the calling program.

Return Value

If the function succeeds, the return value is a nonzero value.

If the function fails, the return value is zero. To get extended error information, call GetLastError.

Requirements

See Also

MessageBox

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Build date: 10/19/2009