looping within a wParam/notification

I'm trying to get the program to loop within a case, and stop if another case happens. So far it works ok for a couple seconds, then it freezes and crashes. It also freezes (not responding) if I click away from notepad, and try to focus my program again. All it does for now is alternate between typing '2' and '3' in notepad. I don't how to go about fixing it so the program does not "not respond" when i try to focus it while it's typing in notepad. Using Devcpp compiler

Code:

case FILE_START:
{
     HWND Handle = FindWindow(NULL, "Untitled - Notepad");
     if(SetForegroundWindow(Handle)){
          SetFocus(Handle);
                    		
          Sleep(1000);
          INPUT inputf1, inputf2;

          ZeroMemory(&inputf1, sizeof(INPUT));
          inputf1.type = INPUT_KEYBOARD;
          inputf1.ki.wVk = VK_NUMPAD2;
							
          ZeroMemory(&inputf2,sizeof(INPUT));
          inputf2.type = INPUT_KEYBOARD;
          inputf2.ki.wVk = VK_NUMPAD3;
							
          while(wParam != FILE_STOP){
               Sleep(500);
               SendInput(1, &inputf1, sizeof(INPUT));
               Sleep(500);
               SendInput(1, &inputf2, sizeof(INPUT));
          }							
     }
}
break;

You don't even know what you're doing with wParam or the callback function you're in.

Consider the following code:

Code:

#include <stdio.h>

void dosomething(int);

int main(void)
{
	dosomething(5);
	dosomething(10);

	return 0;
}

void dosomething(int x)
{
	while(x != 10)
	{
		/* Wait until x is 10. */
	}
}

If the above program makes sense to you and you think it should work, you need to review basic C (or C++). If you understand that it's totally absurd, then look at your own code and realize you're doing the same thing.

Edit: What are you even doing with FindWindow()? *sigh*

I see where I went wrong, but how can I make the program loop the SendInput()'s until a FILE_STOP is called? Also how can I stop the crashes/freezing?

Also how can I stop the crashes/freezing?

By checking the return values of the functions BEFORE you use invalid handle or null pointer?

> while(wParam != FILE_STOP)
Maybe
if(wParam != FILE_STOP)

Where are these messages coming from?


If you want a loop like that, then you need to implement a state machine inside that code
case FILE_START:
- find notepad window
- set focus
- set 1 second timer
case WM_TIMER:
- is notepad still focussed?
- send key1 then key2
case FILE_STOP:
- destroy timer

Notice that none of these states make use of a while loop or sleep.

Originally Posted by Salem

> while(wParam != FILE_STOP)
If you want a loop like that, then you need to implement a state machine inside that code
case FILE_START:
- find notepad window
- set focus
- set 1 second timer
case WM_TIMER:
- is notepad still focussed?
- send key1 then key2
case FILE_STOP:
- destroy timer

Thank you, that's exactly what I needed to know. I got it working correctly now.

Another question so I don't have to start a new thread;

The SendInput() works for sending a simulated keystroke to notepad, or the calculator, or anything else that has text for that matter, but what if i want to call a hotkey. Say in some program F9 is a hotkey for Help on the menu, and I want to call that from another program. SendInput doesn't give the same value as actually pressing the key. Is there a different function (I searched MSDN) that will do that, or is the keyboard press always going to return a different value then simulating it?