需要有关基本Windows C的帮助

Question

I am new to learn creating a WIN32 program using c++, however, when I follow the instructions of a book to try to create my first program, I experience the following problem

#include <windows.h>

const char g_szClassName[] = "myWindowClass";

//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;
    deafult:
        return DefWindowProc(hwnd, msg, wParam, lParam);
}
return 0;
}

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
WNDCLASSEX wc;
HWND hwnd;
MSG Msg;

//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);

if(!RegisterClassEx(&wc))
{
    MessageBox(NULL, "Window Registration Failed!", "Error!", MB_ICONEXCLAMATION | MB_OK);
    return 0;
}

//Step 2: Creating the Window
hwnd = CreateWindowEx(WS_EX_CLIENTEDGE, g_szClassName, "The title of my window", WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, 240, 120, NULL, NULL, hInstance, NULL);
if(hwnd == NULL)
{
    MessageBox(NULL, "Window Creation Failed!", "Error!", MB_ICONEXCLAMATION | MB_OK);
    return 0;
}

ShowWindow(hwnd, nCmdShow);
UpdateWindow(hwnd);

//Step 3: The Message Loop
while(GetMessage(&Msg, NULL, 0, 0) > 0)
{
    TranslateMessage(&Msg);
    DispatchMessage(&Msg);
}
return Msg.wParam;
}

but it keeps returning "Window Creation Failed!", I don't know what's wrong with it and I have done a lot of proofreading. Please help me!

Answer 1

case WM_CLOSE:DestroyWindow(hwnd); break;
case WM_DESTROY:PostQuitMessage(0); break;
deafult:
    return DefWindowProc(hwnd, msg, wParam, lParam);

It might be hard to see, and it's cruel that it compiles because of it being a normal label (though I get a warning from -Wunused-label ), but you misspelled default . This causes WM_NCCREATE to not be handled, which causes your window creation to fail.

It's worth noting that you handle WM_CLOSE in the same way as DefWindowProc , just calling DestroyWindow . You can leave out that case and still end up with the same thing happening when your window is closed.