
在这个消息添加case WM_CREATE:
SetTimer(hWnd,0,1000,NULL)
//创建窗口时设置定时器
2.添加WM_TIMER消息
//---------------------------------------------------------------
case WM_TIMER: //添加定时器处理消息
// 定时器响应函数
OnTimer()
break
3.声明定时器消息响应函数 void
OnTimer()
全部代码看下面
//
// 定时器.cpp : Defines the entry point for the application.
//
#include "stdafx.h"
#include "resource.h"
#define MAX_LOADSTRING 100
// Global Variables:
HINSTANCE hInst // current instance
TCHAR szTitle[MAX_LOADSTRING] // The title bar text
TCHAR szWindowClass[MAX_LOADSTRING] // The title bar text
// Foward declarations of functions included in this code module:
ATOM MyRegisterClass(HINSTANCE hInstance)
BOOL InitInstance(HINSTANCE, int)
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM)
LRESULT CALLBACK About(HWND, UINT, WPARAM, LPARAM)
//定义定时器消息响应函数
void OnTimer()
//声明一个全局句柄获取当前程序实例句柄
HWND g_hWnd
int APIENTRY WinMain(HINSTANCE hInstance,
HINSTANCE hPrevInstance,
LPSTR lpCmdLine,
int nCmdShow)
{
// TODO: Place code here.
MSG msg
HACCEL hAccelTable
// Initialize global strings
LoadString(hInstance, IDS_APP_TITLE, szTitle, MAX_LOADSTRING)
LoadString(hInstance, IDC_MY, szWindowClass, MAX_LOADSTRING)
MyRegisterClass(hInstance)
// Perform application initialization:
if (!InitInstance (hInstance, nCmdShow))
{
return FALSE
}
hAccelTable = LoadAccelerators(hInstance, (LPCTSTR)IDC_MY)
// Main message loop:
while (GetMessage(&msg, NULL, 0, 0))
{
if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg))
{
TranslateMessage(&msg)
DispatchMessage(&msg)
}
}
return msg.wParam
}
//
// FUNCTION: MyRegisterClass()
//
// PURPOSE: Registers the window class.
//
// COMMENTS:
//
//This function and its usage is only necessary if you want this code
//to be compatible with Win32 systems prior to the 'RegisterClassEx'
//function that was added to Windows 95. It is important to call this function
//so that the application will get 'well formed' small icons associated
//with it.
//
ATOM MyRegisterClass(HINSTANCE hInstance)
{
WNDCLASSEX wcex
wcex.cbSize = sizeof(WNDCLASSEX)
wcex.style = CS_HREDRAW | CS_VREDRAW
wcex.lpfnWndProc = (WNDPROC)WndProc
wcex.cbClsExtra = 0
wcex.cbWndExtra = 0
wcex.hInstance = hInstance
wcex.hIcon = LoadIcon(hInstance, (LPCTSTR)IDI_MY)
wcex.hCursor = LoadCursor(NULL, IDC_ARROW)
wcex.hbrBackground = (HBRUSH)(COLOR_WINDOW+1)
wcex.lpszMenuName = (LPCSTR)IDC_MY
wcex.lpszClassName = szWindowClass
wcex.hIconSm = LoadIcon(wcex.hInstance, (LPCTSTR)IDI_SMALL)
return RegisterClassEx(&wcex)
}
//
// FUNCTION: InitInstance(HANDLE, int)
//
// PURPOSE: Saves instance handle and creates main window
//
// COMMENTS:
//
//In this function, we save the instance handle in a global variable and
//create and display the main program window.
//
BOOL InitInstance(HINSTANCE hInstance, int nCmdShow)
{
HWND hWnd
hInst = hInstance// Store instance handle in our global variable
hWnd = CreateWindow(szWindowClass, szTitle, WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, NULL, NULL, hInstance, NULL)
if (!hWnd)
{
return FALSE
}
g_hWnd=hWnd//保存全局句柄 为测试函数绘图使用
ShowWindow(hWnd, nCmdShow)
UpdateWindow(hWnd)
return TRUE
}
//
// FUNCTION: WndProc(HWND, unsigned, WORD, LONG)
//
// PURPOSE: Processes messages for the main window.
//
// WM_COMMAND - process the application menu
// WM_PAINT - Paint the main window
// WM_DESTROY - post a quit message and return
//
//
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
int wmId, wmEvent
PAINTSTRUCT ps
HDC hdc
TCHAR szHello[MAX_LOADSTRING]
LoadString(hInst, IDS_HELLO, szHello, MAX_LOADSTRING)
switch (message)
{
case WM_CREATE:
SetTimer(hWnd,0,1000,NULL)
//创建窗口时设置定时器
break
case WM_COMMAND:
wmId= LOWORD(wParam)
wmEvent = HIWORD(wParam)
// Parse the menu selections:
switch (wmId)
{
case IDM_ABOUT:
DialogBox(hInst, (LPCTSTR)IDD_ABOUTBOX, hWnd, (DLGPROC)About)
break
case IDM_EXIT:
DestroyWindow(hWnd)
break
default:
return DefWindowProc(hWnd, message, wParam, lParam)
}
break
case WM_PAINT:
hdc = BeginPaint(hWnd, &ps)
// TODO: Add any drawing code here...
RECT rt
GetClientRect(hWnd, &rt)
DrawText(hdc, szHello, strlen(szHello), &rt, DT_CENTER)
EndPaint(hWnd, &ps)
break
//---------------------------------------------------------------
case WM_TIMER: //添加定时器处理消息
// 定时器响应函数
OnTimer()
break
//---------------------------------------------------------------
case WM_DESTROY:
PostQuitMessage(0)
break
default:
return DefWindowProc(hWnd, message, wParam, lParam)
}
return 0
}
// Mesage handler for about box.
LRESULT CALLBACK About(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam)
{
switch (message)
{
case WM_INITDIALOG:
return TRUE
case WM_COMMAND:
if (LOWORD(wParam) == IDOK || LOWORD(wParam) == IDCANCEL)
{
EndDialog(hDlg, LOWORD(wParam))
return TRUE
}
break
}
return FALSE
}
void OnTimer()
{
// MessageBox(NULL,_T("定时器启动"),_T("定时器"),MB_YESNO)
//测试定时器是否启动成功
HDC dc=GetDC(g_hWnd) //g_hWnd是定义的全局变量
TextOut(dc,50,50,_T("定时器已经启动"),14)
ReleaseDC(g_hWnd,dc)
}
在/doc/">程序中我们经常要使用定时刷新的功能,典型的应用是在信息管理系统中表单要跟着数据库中的数据变动。MFC提供了定时器来完成这个功能。在MFC中和定时器相关的有三个函数:
UINT SetTimer( UINT nIDEvent, UINT nElapse,
void (CALLBACK EXPORT* lpfnTimer)( HWND, UINT, UINT, DWORD) )
afx_msg void OnTimer( UINT nIDEvent )
BOOL KillTimer( int nIDEvent )
参数说明:
UINT nIDEvent:定时器的ID,给定时器唯一的身份验证,如果在一个/doc/">程序中有多个定时器可以用这个ID来确定是那个定时器发送的消息。
UINT nElapse: 定义刷新时间,即间隔多长时间刷新一次,单位是毫秒。
void (CALLBACK EXPORT* lpfnTimer)( HWND, UINT, UINT, DWORD):
这个回调函数中实现刷新时所做的 *** 作,如在数据库中读取数据。但是我们大多数时候不在这里实现,而是在OnTimer中。
函数功能:
SetTimer用来定义一个定时器的属性,如改定时器的ID,刷新时间,处理函数。
OnTimer实际时系统定义消息用来响应WM_TIMER消息,在这里可以实现对多定时器中的各个定时器分别响应,这里才时定时/doc/">程序大展宏图的地方。 字串2
KillTimer用来结束一个定时器。 字串1
下面我们用一个例子来说明定时器的使用:
这个例子用来实现一个简单的功能,就是在一个单/doc/">文档/doc/">程序中,每间隔5秒d出一个消息框提示“定时器1”,每隔7秒d出一个消息框提示“定时器2”。
建立单/doc/">文档/doc/">程序略,一路Next。
(1)在resource.h中定义两个定时器的ID
#define IDTIMER1 1
#define IDTIMER2 2
(2)在CMainFrame的OnCreate函数中定义两个定时器的属性。
SetTimer(TIMEID1,5000,0)
SetTimer(TIMEID2,7000,0)
(3) CMainFrame中对WM_TIMER进行响应。
void CMainFrame::OnTimer(UINT nIDEvent)
{
// TODO: Add your message handler code here and/or call default
switch(nIDEvent) {
case TIMEID1:
{
AfxMessageBox("定时器1!")
break
} 字串1
case TIMEID2:
{
AfxMessageBox("定时器2!")
break
}
default:
}
CFrameWnd::OnTimer(nIDEvent)
}
(4)在CMainFrame的析构函数中添加
KillTimer(IDTIMER1)
KillTimer(IDTIMER2)
你打算做2次测定工作。第一个2秒内拍入了哪些字符,第二个2秒内拍入了哪些字符。如果你要判断输入的是否是 B, D, 可以自己改一下程序:
去掉 printf("B: %c\n",p)
用:
if ( p == 'B') printf("C\n") 或 if ( (0xff &p) == 'B') printf("C\n") 同你的键盘有关
去掉 printf("E: %c\n",p)
用:
if ( p == 'D') printf("E\n") 或 if ( (0xff &p) == 'D') printf("E\n") 同你的键盘有关
下面 是完整程序。 MS VC++ 6.0 编译器:
#include <stdio.h>
#include <conio.h>
#include <time.h>
int main(){
clock_t t0,dt
int flag
int p
t0 = clock()
printf("=======A========\n")
Lab:
flag = 1
while( !_kbhit() ) {
dt = clock() - t0
if (dt >= 2 * CLOCKS_PER_SEC) flag =0
}
if (flag==0) { printf("2 seconds -- time is over !\n")
} else {
p = _getch()printf("B: %c\n",p)
goto Lab
}
printf("\n=======C=======\n")
t0=clock()
Lab2:
flag = 1
while( !_kbhit() ) {
dt = clock() - t0
if (dt >= 2 * CLOCKS_PER_SEC) flag =0
}
if (flag==0) { printf("2 seconds -- time is over !\n")
} else {
p = _getch()printf("E: %c\n",p)
goto Lab2
}
printf("\n=======D=======\n")
return 0
}
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