win32 application

#include <windows.h>
#include <stdio.h>

LRESULT CALLBACK WinProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam);

int WINAPI WinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd )
{
    //设计一个窗口类
    WNDCLASS wndclass;
    wndclass.cbClsExtra = 0;
    wndclass.cbWndExtra = 0;
    wndclass.hbrBackground = (HBRUSH)GetStockObject(BLACK_BRUSH);
    wndclass.hCursor = LoadCursor(NULL, IDC_CROSS);
    wndclass.hIcon = LoadIcon(NULL, IDI_ERROR);
    wndclass.hInstance = hInstance; //应用程序句柄由WinMain函数传进来
    wndclass.lpfnWndProc = WinProc;
    wndclass.lpszClassName = "WinTest";
    wndclass.lpszMenuName = NULL;
    wndclass.style = CS_HREDRAW | CS_VREDRAW;
    RegisterClass(&wndclass);

    HWND hwnd = CreateWindow(wndclass.lpszClassName, "TEst",
        WS_OVERLAPPEDWINDOW, 0, 0, 600, 400, NULL, NULL, hInstance, NULL);

    ShowWindow(hwnd, SW_SHOWNORMAL);
    UpdateWindow(hwnd);

    MSG msg;
    BOOL bRet;
    while( (bRet = GetMessage(&msg, NULL, 0, 0)) != 0)
    {
        if(bRet == -1)
        {
            //handle the error and possibly exit
            return -1;
        }
        else
        {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
    }

    return msg.wParam;
}

LRESULT CALLBACK WinProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    switch(uMsg)
    {
    case WM_CHAR:
        {
            char szChar[20];
            sprintf(szChar, "char code is %d", wParam);
            MessageBox(hwnd, szChar, "char", 0);
        }
        break;
    case WM_LBUTTONDOWN:
        {
            MessageBox(hwnd, "Mouse clicked", "message", 0);
            HDC hdc = GetDC(hwnd);//不能在WM_PAINT消息中调用
            TextOut(hdc, 0, 50, "程序员", strlen("程序员"));
            ReleaseDC(hwnd, hdc);
        }
        break;
    case WM_PAINT:
        {
            PAINTSTRUCT ps;
            HDC hdc = BeginPaint(hwnd, &ps);//只能在响应WM_PAINT中调用
            TextOut(hdc, 0, 0, "http://www", strlen("http://www"));
            EndPaint(hwnd, &ps);
        }
        break;
    case WM_CLOSE:
        {
            if(IDYES == MessageBox(hwnd, "是否结束？", "message", MB_YESNO))
            {
                DestroyWindow(hwnd);
            }
        }
        break;
    case WM_DESTROY:
        {
            PostQuitMessage(0);
        }
        break;
    default:
        {
            return DefWindowProc(hwnd, uMsg, wParam, lParam);
        }

    }//end of switch

    return false;
}