Send some keys to inactive window with python

Question

I'm trying to send some keys to an inactive window/process/program (Win32/64) using Python. Already read about pywinauto and SendKeys, but both of them activate the window before sending keys.

Is there any way to work with an inactive window without activating it?

It would be great if someone posted a simple example/snippet.

Answer 1

This is a really old post but there has not been an answer here, I was looking for something exactly like this, and I had spend 6 hours going through Stackoverflow, and ended up just reading all the C documentation because it was more useful.

#you will need the win32 libraries for this snippet of code to work, Links below
import win32gui
import win32con
import win32api
from time import sleep

#[hwnd] No matter what people tell you, this is the handle meaning unique ID, 
#["Notepad"] This is the application main/parent name, an easy way to check for examples is in Task Manager
#["test - Notepad"] This is the application sub/child name, an easy way to check for examples is in Task Manager clicking dropdown arrow
#hwndMain = win32gui.FindWindow("Notepad", "test - Notepad") this returns the main/parent Unique ID
hwndMain = win32gui.FindWindow("Notepad", "test - Notepad")

#["hwndMain"] this is the main/parent Unique ID used to get the sub/child Unique ID
#[win32con.GW_CHILD] I havent tested it full, but this DOES get a sub/child Unique ID, if there are multiple you'd have too loop through it, or look for other documention, or i may edit this at some point ;)
#hwndChild = win32gui.GetWindow(hwndMain, win32con.GW_CHILD) this returns the sub/child Unique ID
hwndChild = win32gui.GetWindow(hwndMain, win32con.GW_CHILD)

#print(hwndMain) #you can use this to see main/parent Unique ID
#print(hwndChild)  #you can use this to see sub/child Unique ID

#While(True) Will always run and continue to run indefinitely
while(True):
    #[hwndChild] this is the Unique ID of the sub/child application/proccess
    #[win32con.WM_CHAR] This sets what PostMessage Expects for input theres KeyDown and KeyUp as well
    #[0x44] hex code for D
    #[0]No clue, good luck!
    #temp = win32api.PostMessage(hwndChild, win32con.WM_CHAR, 0x44, 0) returns key sent
    temp = win32api.PostMessage(hwndChild, win32con.WM_CHAR, 0x44, 0)

    #print(temp) prints the returned value of temp, into the console
    print(temp)
    #sleep(1) this waits 1 second before looping through again
    sleep(1)

I've seen posts all over to use

hwndEdit = win32gui.FindWindowEx(hwndMain, hwndChild, "Edit", "test - Notepad");

but I could never figure it out. In addition to that all documentation on Microsoft's site is vary ambiguous, So I've added my own of how I understand it.

That should get you started and should be helpful for others. If anyone else had revisions let me know.

Win32 Python Library