How to automate Pasting with SendMessage in AutoHotkey

In this demo I walk through another way to automate pasting with sendmessage in AutoHotkey to a given window / control. Sending paste to a window is easy with AutoHotkey. Sometimes I'd like a more robust way to automate pasting. Here I show how to use Sendmessage in AutoHotkey

[hrgwea]

It would be awesome if Windows had a mandatory and standard way of informing a window that it must paste the content of the clipboard.
Just like there's a standard way of programmatically closing, maximizing, minimizing, etc.

The PASTE system message is way too unreliable. The only reliable way is by injecting a CTRL+C keystroke, which is full of problems associated to timing, modifier key states and system focus.