I\'m messing around with Win32 API and windows messaging trying to figure out how things work and I found this question very helpful.
I\'d like to improve upon the solut
Send EM_SETSEL
to put the caret to the end of the edit window. Then send EM_REPLACESEL
to append text.
This is much better than reading the entire contents, appending your addition and then setting the entire contents if the edit control contains a large amount of text.
These methods can cross 32/64 bit process boundaries without difficulty.