What is uMsg????

I've just start to program in windows and I was wondering was uMsg is. Ive seen it like a prototype

LRESULT CALLBACK WndProc(HWND hWnd,UINT uMsg,WPARAM wParam,LPARAM lParam);

and I cant figure it out what it is??? Could someone please enlight me
Thx in advance

You see, when you declare/define a window procedure, you specify the parameters.

-type HWND is the window in which the message is being sent-
-type UINT (your uMsg) is a simple number that specifies the message being sent to your window procedure-
-type WPARAM is just another part of the message you can process-
-type LPARAM is another part of the message you can process-

the uMsg is the actual message sent to your window, you should make a big switch and make a handler for each message of your interest

Oskilian

Yeah, uMsg is pretty much what you base your decisions (the program's decisions) on.

--Garfield

I made a simply windows app with the console still enabled and put a cout in my callback function and found that it calls my callback function everytime the mouse moves jsut a little bit, passing my pointer across the window causes my function to be called at least a hundred times, if I didn't need to do anything when the mouse is moved should I make my callback function something like for the purose of not doing much processing just for a little mouse movment

Code:

---


LRESULT CALLBACK MsgHandler(HWND hwnd, UINT msg, WPARAM wparam, LPARAM lparam)
{
    switch(msg)
   
case(WM_MOUSEMOVE)://or whatever the mouse move message is
    {
        return(DefWindowProc(hwnd, msg, wparam, lparam));// Don't do anything cause I don't need to or call another function to handle the movement
    }
    default:
    {
    // Call another function to handle other messages
    if(ScndMsgHandler(HWND hwnd, UINT msg, WPARAM wparam, LPARAM lparam))return (1);
    else
  {
  return(DefWindowProc(hwnd, msg, wparam, lparam));
  }
}

---

I'm sure I've gotten the switch case syntax wrong, but you got the idea

So that a long switch case with all the messsages doesn't have to be processed for the frequent mouse movements

I'm asking would it be a good way to do things? I'm wondering on the side of my mind how exactly a switch case is processed, how much longer it takes if more messages are added to it

If you do not want to process mouse msg's don't.
Ignore them.

Also use

case WM_COMMAND://or what ever
break;

and the return at the end of the switch.

But I don't want it to search through a long switch case a hundred times everytime someone passes a mouse over my window.

Um...that's what the window procedure is. Just one big switch case test.

--Garfield

But instead of having that long switch case in the first function, I can have the switch case for all the messages I want to handle in a secondary procedure, and in the main procedure check to see if it's just an annoying mouse movement , if it's not then I call the second procedure. That way I don't process the long switch case everytime the system calls my procedure because of a move message, and move messages happen many many times more than any other meaningful message. Look at the code I posted. I don't mean to sound like I'm the end all of it, I haven't been doing winapi for long, I just don't think you see what I'm getting at. If you create a console win32 project and make a window and in the callback procedure function put a cout<<Msg; you'll see everytime you move the mouse just a tiny bit the function gets called and it's just about always the same message, assuming it's the mouse move message, but I only see it as an integer when it's outputted of course.