SendMessage

SendMessage(<hwnd>, <msg> [, <wparam>[, <lparam>[, <retindex>]]])

Wrapper for the standard SendMessage API function.

Parameters

hwnd	Window handle.
msg	Numeric message number.
wparam lparam	Message options. If one or both parameters are omitted, NULL will be passed. If the parameter is interpreted as a number, it will be passed as a number, otherwise as a string address.
retindex	If the message returns text in a buffer, specifies which of the parameters should buffer the return value and should be returned by the function. Can take the value 1 (wparam) and 2 (laparam). The default value is 0, in which case the function will return a numeric SendMessage result.

Remarks

If retindex is zero, then immediately after calling the SendMessage function, the GetLastError function will be called, the result of which will be returned by the ERROR macro, i.e., it may contain numerical error code.

If retindex is greater than zero, ERROR will contain the numeric result of the SendMessage. It will not be possible to get an error code for such a call.

Passing strings in function parameters is possible only for system messages that allow passing strings between processes, such as WM_SETTEXT.

The function executes the Unicode version of SendMessage. The buffer size for receiving text is 65535 2-byte characters.