//【例2.2】顯示一個(gè)窗口的Windows應(yīng)用程序。

#include<windows.h>  //包含windows.h頭文件
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM );//窗口函數(shù)聲明
/*入口函數(shù) WinMain()*/
int APIENTRY WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
                    LPSTR lpCmdLine,int nCmdShow) {
    WNDCLASS wndclass;		//定義窗口類結(jié)構(gòu)變量
    HWND hwnd; 			//定義窗口句柄
    MSG msg;			//定義消息結(jié)構(gòu)變量
       				//以下定義窗口類各屬性
    wndclass.style = CS_HREDRAW|CS_VREDRAW;//改變窗口口大小則重畫
    wndclass.lpfnWndProc = WndProc; 		//窗口函數(shù)為  WndProc
	wndclass.cbClsExtra = 0;				//窗口類無擴(kuò)展
	wndclass.cbWndExtra = 0;				//窗口實(shí)例無擴(kuò)展
    wndclass.hInstance = hInstance;    //注冊(cè)窗口類的實(shí)例句柄
    wndclass.hIcon = LoadIcon(NULL,IDI_APPLICATION);//窗口用默認(rèn)光標(biāo)
    wndclass.hCursor = LoadCursor(NULL,IDC_ARROW);  //顯口用箭頭光標(biāo)
    wndclass.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
	//背景為白色
	wndclass.lpszMenuName = NULL;			//窗口缺省無菜單
    wndclass.lpszClassName = "Ex2_2"; 	 //窗口類名為Ex2_2
	//注冊(cè)窗口類。若失敗則返回
    if(! RegisterClass(&wndclass)) return FALSE; 
       //創(chuàng)建窗口
    hwnd = CreateWindow("Ex2_2",			//窗口類名  Ex2_2
						"Ex2_2",				//窗口名EX2_2
						WS_OVERLAPPEDWINDOW, 	//重疊式窗口風(fēng)格
						CW_USEDEFAULT,	CW_USEDEFAULT,//左上角屏幕坐標(biāo)
						CW_USEDEFAULT, CW_USEDEFAULT,//寬度和高度
                        NULL,				//此窗口無父窗口
                        NULL,				//此窗口無主菜單
                        hInstance,				//創(chuàng)建此窗口的實(shí)例句柄
                        NULL);				//此窗口無創(chuàng)建參數(shù)
       //顯示并更新窗口
	ShowWindow(hwnd,nCmdShow);			//顯示窗口
    UpdateWindow(hwnd);					//更新窗口的客戶區(qū)
       //消息循環(huán)
    while(GetMessage(&msg,NULL,0,0)) {	    //獲取消息，遇WM_QUIT退出循環(huán)
      	TranslateMessage(&msg);		//鍵盤消息轉(zhuǎn)換
       	DispatchMessage(&msg);		//派送消息給窗口函數(shù)
       }
    return msg.wParam;						//返回退出值
}
//窗口函數(shù)
LRESULT CALLBACK WndProc(HWND hwnd,UINT message,
WPARAM wParam, LPARAM lParam){
	switch(message)	 {  //根據(jù)消息值轉(zhuǎn)相應(yīng)的消息處理
	case WM_PAINT:			//重畫窗口客戶區(qū)消息
              HDC hdc;			//定義設(shè)備描述表句柄
              PAINTSTRUCT ps;		//定義繪圖信息結(jié)構(gòu)變量
              hdc = BeginPaint(hwnd,&ps);	//獲取需重畫窗口的設(shè)備描述表句柄
              TextOut(hdc, 0, 0,"This is my Windows application．",26);  //輸出文本,僅顯示了26個(gè)字母
              EndPaint(hwnd,&ps);		//結(jié)束要重畫的窗口
              return 0;
	case  WM_DESTROY:			//撤消窗口消息
              PostQuitMessage(0);		//產(chǎn)生退出程序消息WM_QUIT
              return 0;
    }
    return DefWindowProc(hwnd, message, wParam, lParam);  //其它轉(zhuǎn)缺省窗口函數(shù)
}