A few Windows prog questions

I am learning Windows programming from Charles Petzold's Programming Windows 5th Edition. Well, I decided to take a look at www.winprog.org to take a look at the tutorial. Well, it seems to have contrasting code with Petzold. For instance

Code:

---

    //Step 1: Registering the Window Class
    wc.cbSize        = sizeof(WNDCLASSEX);
    wc.style        = 0;
    wc.lpfnWndProc  = WndProc;
    wc.cbClsExtra    = 0;
    wc.cbWndExtra    = 0;
    wc.hInstance    = hInstance;
    wc.hIcon        = LoadIcon(NULL, IDI_APPLICATION);
    wc.hCursor      = LoadCursor(NULL, IDC_ARROW);
    wc.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
    wc.lpszMenuName  = NULL;
    wc.lpszClassName = g_szClassName;
    wc.hIconSm      = LoadIcon(NULL, IDI_APPLICATION);

---

Well, I never learned that last field of the Window class (wc.hIconSm). What is that?

Code:

---

// Step 4: the Window Procedure
LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    switch(msg)
    {
        case WM_CLOSE:
            DestroyWindow(hwnd);
        break;
        case WM_DESTROY:
            PostQuitMessage(0);
        break;
        default:
            return DefWindowProc(hwnd, msg, wParam, lParam);
    }
    return 0;
}

---

And their WndProc, I didn't learn with the WM_CLOSE. What is that when you have WM_DESTROY? Does it just go to WM_DESTROY?

Thanks.

--Garfield the Great

>>Well, I never learned that last field of the Window class (wc.hIconSm). What is that?

this is the small icon that windows uses(like in your explorer)
You can use a different icon for it because otherwise windows just removes some lines from your icon and it can get messed up


>>And their WndProc, I didn't learn with the WM_CLOSE. What is that when you have WM_DESTROY? Does it just go to WM_DESTROY?

A WM_CLOSE is sent when u press the X in the upper right corner.
A WM_DESTROY is sent when you use DestroyWindow(hwnd);

don't shoot me if this is wrong, Im'only learnig myself

Thanks for the reply!

--Garfied the Great

I was just looking at the tutorial more, and I found that the window class data type isn't

WNDCLASS

it is

WNDCLASSX

Anybody know what that means?

--Garfield the Great

WNDCLASSEX just has some extra members (hIconSm and cbSize)
cbSize is the size of the structure

Why would you want to use WNDCLASSEX? What are the benefits?

don't know. I almost never use it. I gues you would use it when you want a small icon. maybe there are some other benefits but I can't find any

Okay, thanks for the explanation!

Code:

---

case WM_CLOSE: // sent when [X] is clicked, or ALT-F4
            DestroyWindow(hwnd);        // Destroy the Window message
        break; // wait for user to respond before destroying window
case WM_DESTROY:// if WM_CLOSE is done, then close window
            PostQuitMessage(0);

---

Thanks for the explanation.

The only benefit of WNDCLASSEX over WNDCLASS is the small icon deal. that's it, unless you can find some crazy use for defining the size of the structure.