windows api学习笔记-使用定时器

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#include <windows.h>

#include "resource.h"

#include <string>

 

LRESULT CALLBACK MainWndProc(HWND,UINT,WPARAM,LPARAM);//窗口函数的函数原型

 

int APIENTRY WinMain(                               //APIENTRY是__stdcall的宏定义

                     HINSTANCE hInstance,           //本模块的实例句柄

                     HINSTANCE hPrevInstance,       //Win16留下的废物

                     LPSTR lpCmdLine,               //命令行参数

                     int nCmdShow                   //主窗口初始化时的现实形式

                     )

{

    char szClassName[] = "MainClass";

    WNDCLASSEX wndclass;   //用来描述主窗口的结构

    wndclass.cbSize = sizeof(wndclass);  //结构的大小

    wndclass.style = CS_HREDRAW|CS_VREDRAW; //如果窗口大小，横向改变和竖向改变都会重画窗口

    wndclass.lpfnWndProc = MainWndProc;//窗口函数指针

    wndclass.cbClsExtra = 0;//没有额外的类内存

    wndclass.cbWndExtra = 0;//没有额外的窗口内存

    wndclass.hInstance = hInstance;//实例句柄

    wndclass.hIcon = ::LoadIcon(NULL,IDI_APPLICATION);//使用预定义图标

    wndclass.hCursor = ::LoadCursor(NULL,IDC_ARROW);//使用预定义光标

    wndclass.hbrBackground = (HBRUSH)::GetStockObject(WHITE_BRUSH);//使用白色背景画刷

    wndclass.lpszMenuName = (LPSTR)IDR_MENU1;//指定菜单,菜单在头文件中已经定义了

    wndclass.lpszClassName = szClassName;//窗口类的名称

    wndclass.hIconSm = NULL;//没有类的小图标

 

    ::RegisterClassEx(&wndclass);//注册这个窗口类

 

    HWND hwnd = ::CreateWindowEx(

        0,//扩展样式

        szClassName,//类名

        "My First Window",//窗口名。标题

        WS_OVERLAPPEDWINDOW,//窗口风格

        CW_USEDEFAULT,//初始X坐标

        CW_USEDEFAULT,//初始Y坐标

        CW_USEDEFAULT,//宽度

        CW_USEDEFAULT,//高度

        NULL,//父窗口句柄

        NULL,//菜单句柄

        hInstance,//实例句柄

        NULL//用户数据

        );

    if(hwnd == NULL)

    {

        ::MessageBox(NULL,"创建窗口出错","系统提示",MB_OK);

    }

    ::ShowWindow(hwnd,nCmdShow);//显示窗口

    ::UpdateWindow(hwnd);//刷新窗口

    MSG msg;

    while(::GetMessage(&msg,NULL,0,0))

    {

        ::TranslateMessage(&msg);//转换为键盘消息

        ::DispatchMessage(&msg);//将消息发送到相应的窗口函数

    }

    return msg.wParam;//当GetMessage返回FALSE时程序结束

}

 

#define IDT_TIMER1  1

 

LRESULT CALLBACK MainWndProc(HWND hwnd,UINT message,WPARAM wParam,LPARAM lParam)

{

    char szText[56];

    static int nNum;

    static int bSetTimer;// 指示是否安装了定时器

    HDC hdc;

    PAINTSTRUCT ps;

    switch(message)

    {

        case WM_CREATE:

            {

                ::SetWindowText(hwnd,"定时器");

                bSetTimer = FALSE;

                return 0;

            }

        case WM_PAINT:

            {

                hdc = ::BeginPaint(hwnd,&ps);//使无效的客户区变的有效，并取得设备环境句柄               

                ::EndPaint(hwnd,&ps);

                return 0;

            }

        case WM_DESTROY:

            {

                ::PostQuitMessage(0);//向消息队列投递一个WM_QUIT消息，促使GET MESSAGE函数返回0，结束消息循环

                return 0;

            }

        case WM_COMMAND:

            {

                switch(LOWORD(wParam))

                {

                    case ID_FILE_EXIT:

                        ::SendMessage(hwnd,WM_CLOSE,0,0);

                        break;

                }

                return 0;

            }

        case WM_LBUTTONDOWN:

            {

                if(bSetTimer)

                {

                    ::KillTimer(hwnd,IDT_TIMER1);

                    bSetTimer = FALSE;

                }

                else

                {

                    if(::SetTimer(hwnd,IDT_TIMER1,600,NULL) == 0)

                    {

                        ::MessageBox(hwnd,"定时器安装失败","系统提示",MB_OK);

                    }

                    else

                    {

                        bSetTimer = TRUE;

                    }

                }

                break;

            }

        case WM_TIMER:

            {

                if(wParam == IDT_TIMER1)

                {

                    hdc = ::GetDC(hwnd);

                    nNum++;

                    ::wsprintf(szText,"计数：%d",nNum);

                    ::TextOut(hdc,10,10,szText,strlen(szText));//输出文本

                    ::InvalidateRect(hwnd,NULL,0);

                    ::MessageBeep(MB_OK);

                }

            }

            break;

    }

    return ::DefWindowProc(hwnd,message,wParam,lParam);

}