BackGround

[criya]

I have many questions,
1.Can anyone help me on this issue,i want to change my background color of client area in my window whenever i click & drag my left mouse button,i did with setbkcolor() but it's not working,why?

2.What is the use of WS_MINIMIZE?

3.I read that wparam & lparam messages sent to the windowprocedure is different for each message sent.Is it true?If means then each time what value is sent for these 2 parameters during each message?

4.What is the difference btwn WM_QUIT & WM_DESTROY,why we are using WM_DESTROY only mostly & not WM_QUIT?

Advance Thanks!!!

[guestgulkan]

1. setbkcolor() is for when displaying text within a window (e.g when using the TextOut function).
You set the actual backgound colour for
a particular window class when registering the window class here:

WNDCLASSEX wcex = {0};

  wcex.cbSize		= sizeof(WNDCLASSEX);
  wcex.lpfnWndProc	= WndProc;
  wcex.hInstance		= hInstance;
  wcex.hCursor		= LoadCursor(NULL, IDC_ARROW);
  wcex.hbrBackground	= (HBRUSH)(COLOR_WINDOW+1); //<<======Here
  wcex.lpszClassName	= "MAIN";
  wcex.hIconSm		= LoadIcon(NULL,IDC_ARROW);

  RegisterClassEx(&wcex);

and/or you can set it for an individual window by intercepting the WM_ERASEBKGND and WM_PAINT messages and doing it there.


2.WS_MINIMIZE - (Windows style MINIMIZE(d) - the window will start off in the iconized state).

3. wparam & lparam messages are NOT messages.
The windows procedure parameters look something like this:
LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
As you can see the actual message (such as WM_CREATE) is a unsigned integer.
The wparam amd lparam may carry extra information about the message.
For example :
For the WM_PAINT message both wparam and lparam are 0 (zero).
For the WM_CREATE message, wparam is not used, lparam is a pointer to a CREATESTRUCT

4.The usual method of closing an application goes something like this:
4a. User slects close from the main menu or clicks the X button.
4b. Windows sent WM_CLOSE message.
4c. Programmer intercepts WM_CLOSE message, confirms Close request, and calls DestroyWindow() function
(Note if programmer does not intercept the WM_CLOSE message, the default windows procedure will call DestroyWindow() function)

4d. The DestroyWindow() functions, destroys the window (what else) and sends a WM_DESTROY message.

4e. Programmer intercepts WM_DESTROY message - does any final cleanup and calls PostQuitMessage() function.
(or the default windows procedure does it for you)

4f. The PostQuitMessage() function sends a WM_QUIT message, which cause the message loop to stop processing
and the application to exit.

[george135]

All of this is clearly explained in MSDN, in details
RTFM.