EM_GETTHUMB
An
application sends the EM_GETTHUMB message to retrieve the position of the
scroll box (thumb) in a multiline edit control.
EM_GETTHUMB
wParam = 0;
// not used, must be zero
lParam = 0;
// not used, must be zero
Parameters
This message
has no parameters.
Return Values
The return
value is the position of the scroll box.