dev c++实现图形界面定时关机（windows）

//shutdown_windows.c
#include<windows.h>
#include<stdio.h>
char str[];
char cmd[];
//char hour[10], minute[10];
int num;
int num_text_hour, num_text_minute;
//char num_str[];
LRESULT CALLBACK WndProc(HWND,UINT,WPARAM,LPARAM);
int WINAPI WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance, LPSTR lpCmdLine,int nCmdShow)
{
HWND hWnd;
MSG Msg;
WNDCLASS WndClass;
WndClass.style=CS_HREDRAW|CS_VREDRAW;
WndClass.lpfnWndProc=WndProc;
WndClass.cbClsExtra=0;
WndClass.cbWndExtra=0;
WndClass.hInstance=hInstance;
WndClass.hIcon=LoadIcon(NULL,IDI_APPLICATION);
WndClass.hCursor=LoadCursor(NULL,IDC_ARROW);
WndClass.hbrBackground=(HBRUSH)GetStockObject(WHITE_BRUSH);
WndClass.lpszMenuName=NULL;
WndClass.lpszClassName="Hello Win";   //窗口类名
//注册窗口
if(!RegisterClass(&WndClass))
{
MessageBox(NULL,"窗口注册失败!","Hello Win",0);
return 0;
}
//创建窗口
hWnd=CreateWindow("Hello Win", "定时关机--junmuzi", WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, NULL, NULL, hInstance, NULL);
//显示窗口
ShowWindow(hWnd,nCmdShow);
//更新窗口
UpdateWindow(hWnd);
//进入消息循环：当从应用程序消息队列中捡取的消息是WM_QUIT时，则推出循环
while(GetMessage(&Msg,NULL,0,0))
{
TranslateMessage(&Msg);  //转换键盘消息
DispatchMessage(&Msg);   //分发消息
}
return Msg.wParam;
}

LRESULT CALLBACK WndProc(HWND hWnd,UINT message,WPARAM wParam,LPARAM lParam)
{
HDC hDC;
PAINTSTRUCT Ps;
char strEdit_hour[10], strEdit_minute[10];
static HWND hWndButton_ok, hWndButton_cancel, hWndEdit_hour, hWndEdit_minute;
switch(message)
{
case WM_CREATE:
hWndEdit_hour = CreateWindow("edit",NULL,WS_CHILD|WS_VISIBLE|WS_BORDER,10,60,100,25,hWnd,NULL,NULL,NULL);
hWndEdit_minute = CreateWindow("edit",NULL,WS_CHILD|WS_VISIBLE|WS_BORDER,180,60,100,25,hWnd,NULL,NULL,NULL);
hWndButton_ok = CreateWindow("button","确定",WS_CHILD|WS_VISIBLE|WS_BORDER, 340, 60, 100, 25, hWnd,NULL,NULL,NULL);
hWndButton_cancel = CreateWindow("button","取消定时关机",WS_CHILD|WS_VISIBLE|WS_BORDER, 460, 60, 100, 25, hWnd,NULL,NULL,NULL);
return 0;
case WM_COMMAND:
if(((HWND)lParam==hWndButton_ok)&&(HIWORD(wParam)==BN_CLICKED))
//按下按键hWndButton_ok
{
num_text_hour = GetWindowText(hWndEdit_hour,strEdit_hour,10);     //获取编辑框控件hour的内容
//sprintf(str,"The result is: %s",strEdit_hour);
//sprintf(hour, "%s", strEdit_hour);
if (num_text_hour == 0)
{
MessageBox(NULL,"小时数不能为空!","错误信息：", MB_OK);
}
num_text_minute = GetWindowText(hWndEdit_minute,strEdit_minute,10);     //获取编辑框控件minute的内容
if (num_text_minute == 0)
{
MessageBox(NULL,"分钟数不能为空!","错误信息：", MB_OK);
}
if ((num_text_hour != 0) && (num_text_minute != 0))
{
num = atoi(strEdit_hour) * 3600 + atoi(strEdit_minute) * 60;    //把小时和分钟数转化为多少秒
//itoa(num, num_str, 10);
//sprintf(str,"The result is: %s",strEdit_minute);
//sprintf(minute, "%s", strEdit_minute);
//strcat(cmd, str_);
//sprintf(cmd, "shutdown -s -t %s %s %d", strEdit_hour, strEdit_minute, num);
sprintf(cmd, "shutdown -s -t %d", num);    //
sprintf(str, "电脑会在%s小时%s分钟后关机！！！", strEdit_hour, strEdit_minute);
system(cmd);     //shutdown the computer.
InvalidateRect(hWnd,NULL,TRUE);
}
}
if(((HWND)lParam == hWndButton_cancel)&&(HIWORD(wParam) == BN_CLICKED))
//按下按键hWndButton_cancel
{
sprintf(cmd, "shutdown -a");    //
sprintf(str, "电脑定时关机被取消！！！");
system(cmd);     //shutdown the computer.
InvalidateRect(hWnd,NULL,TRUE);
}
case WM_PAINT://设计编辑框
hDC=BeginPaint(hWnd,&Ps);
TextOut(hDC,10,10,"请输入你要设置的多长时间后关机（小时和分钟数）：",48);
TextOut(hDC,120,60,"小时",4);
TextOut(hDC,290,60,"分钟",4);
//TextOut(hDC,10,90,str,strlen(str));
TextOut(hDC,10,90,str,strlen(str));
EndPaint(hWnd,&Ps);
return 0;
case WM_DESTROY:
PostQuitMessage(0);
return 0;
}
return DefWindowProc(hWnd,message,wParam,lParam);
}