RegisterWindowMessage
The RegisterWindowMessage
function defines a new window message that is guaranteed to be unique
throughout the system. The returned message value can be used when calling the SendMessage or PostMessage function.
UINT RegisterWindowMessage(
|
LPCTSTR lpString |
// address of
message string |
|
); |
|
Parameters
lpString
Points to a
null-terminated string that specifies the message to be registered.
Return Values
If the
message is successfully registered, the return value is a message identifier in
the range 0xC000 through 0xFFFF.
If the
function fails, the return value is zero.
Remarks
The RegisterWindowMessage
function is typically used to register messages for communicating between two
cooperating applications.
If two
different applications register the same message string, the applications
return the same message value. The message remains registered until the Windows
session ends.
Only use RegisterWindowMessage
when more than one application must process the same message. For sending
private messages within a window class, an application can use any integer in
the range WM_USER through 0x7FFF. (Messages in this range are private to a
window class, not to an application. For example, predefined control classes
such as BUTTON, EDIT, LISTBOX, and COMBOBOX may use values in this range.)
See Also