What Sendmessage To Use To Send Keys Directly To Another Window?

I'm trying to use SendMessage to send keyboard input to another window. I know the drawbacks, but I have to do it since I have to send several keys and I can't guarantee that the w

Solution 1:

When I wrote the question, I understood that SendKeys is the correct way to generate keyboard input, and that's the only one that works in all cases. However, I couldn't use SendKeys, cause the computer my program is running on will be actively used while my program is running, meaning a mouse-click can happen at any time that will change the focus of the window and make SendKeys start sending input to the wrong window.

What I wanted to know was just why in particular my code wasn't working - was I doing something wrong with the types of messages I was sending? Post vs. Send? What should WPARAM be? Etc... The answer was probably cause I was sending the messages to the Notepad window, and not to the edit control found inside Notepad - I suspect that will work.

Anyway, I tried sending input to the app I wanted it to actually work on, and this ended up working:

def send_input_hax(hwnd, msg):
    for c in msg:
        if c == "\n":
            win32api.SendMessage(hwnd, win32con.WM_KEYDOWN, win32con.VK_RETURN, 0)
            win32api.SendMessage(hwnd, win32con.WM_KEYUP, win32con.VK_RETURN, 0)
        else:
            win32api.SendMessage(hwnd, win32con.WM_CHAR, ord(c), 0)

So the answer is that I wasn't doing anything wrong in terms of the message types or the contents of the message, it was just to an incorrect destination.