Sending CTRL-S message to a window

Question

I want to save a TextPad window using C# code; I can find out the handle of the window but not sure how to send CTRL - S to that window. I want to use P/Invoke API to achiev

Answer 1

You cannot use SendMessage (or PostMessage, the correct one) to simulate the state of the modifiers keys, like CTRL. You must use SendInput().

A keystroke like Ctrl+S is not untypically translated into a WM_COMMAND message. Use the Spy++ tool to see what happens when you type Ctrl+S by hand. If you see WM_COMMAND then you're golden, you can use SendMessage() to send that message. This will of course only work on a specific process.