关于定时器的实现

[lzxjxsy]

各位大哥,关于定时器的实现和应用,请大家帮我看看,下面两段代码有什么不同,为什么一个能实现定时功能,一个不能实现.

不能实现的如下:
#include <windows.h>
#include <process.h>
#include <stdio.h>
VOID CALLBACK TimerHandler( HWND hwnd, UINT uMsg, UINT_PTR idEvent, DWORD dwTime)
{
printf("ok!\n");
}

class clsTimer{
public:
static int setOneTimer(int nInterval, TIMERPROC taskFun);
void start();

static void gTaskThreadFunc(LPVOID pParam);
};

void clsTimer::start()
{

Sleep(1000);
_beginthread(gTaskThreadFunc, 0, NULL);
}

void clsTimer::gTaskThreadFunc(LPVOID pParam)
{
// setOneTimer(1000, (TIMERPROC)TimerHandler);
while(true)
{
MSG message;
Sleep(1);
while (::PeekMessage(&message, NULL, 0, 0, PM_REMOVE))
{
::TranslateMessage(&message);
::DispatchMessage(&message);
}
}
}

int clsTimer::setOneTimer(int nInterval, TIMERPROC taskFun)
{
return SetTimer(NULL, 0, nInterval, taskFun);
}

int main()
{
clsTimer ct;
ct.setOneTimer(1000, (TIMERPROC)TimerHandler);
ct.start();

while(1)
{
Sleep(1000);
}
return 0;
}


能实现的如下:
#include <windows.h>
#include <process.h>
#include <stdio.h>
VOID CALLBACK TimerHandler( HWND hwnd, UINT uMsg, UINT_PTR idEvent, DWORD dwTime)
{
printf("ok!\n");
}

class clsTimer{
public:
static int setOneTimer(int nInterval, TIMERPROC taskFun);
void start();

static void gTaskThreadFunc(LPVOID pParam);
};

void clsTimer::start()
{

Sleep(1000);
_beginthread(gTaskThreadFunc, 0, NULL);
}

void clsTimer::gTaskThreadFunc(LPVOID pParam)
{
setOneTimer(1000, (TIMERPROC)TimerHandler);
while(true)
{
MSG message;
Sleep(1);
while (::PeekMessage(&message, NULL, 0, 0, PM_REMOVE))
{
::TranslateMessage(&message);
::DispatchMessage(&message);
}
}
}

int clsTimer::setOneTimer(int nInterval, TIMERPROC taskFun)
{
return SetTimer(NULL, 0, nInterval, taskFun);
}

int main()
{
clsTimer ct;
// ct.setOneTimer(1000, (TIMERPROC)TimerHandler);
ct.start();

while(1)
{
Sleep(1000);
}
return 0;
}

拜托大家了,如果解答得好,兄弟再开贴给分，绝不食言。两段代码的区别是setOneTimer(1000, (TIMERPROC)TimerHandler); 的位置不同

[hxzmm]

This window must be owned by the calling thread.
这是SetTimer的hWnd参数的解释！！只能在同一个线程当中！！

[lzxjxsy]

可否提供一下更加详细的资料啊，拜托了。你这句话是从哪里摘来的啊，谢谢了。

[一条晚起的虫]

msdn

[Stefine]

同意一楼

An application can process WM_TIMER messages by including a WM_TIMER case statement in the window procedure or by specifying a TimerProc callback function when creating the timer. When you specify a TimerProc callback function, the default window procedure calls the callback function when it processes WM_TIMER. Therefore, you need to dispatch messages in the calling thread, even when you use TimerProc instead of processing WM_TIMER.

PS: 请KillTimer

[lzxjxsy]

我就是想问为什么在不同的线程里面他们不能响应，应为根据msdn上的说明，应该是可以的，应为PeekMessage第一个参数为null，应该接受该应用程序的所有消息，而且SetTimer的参数还可以为空，这时候不指定任何form.

[liuqiyc]

If hWnd is NULL, PeekMessage retrieves messages for any window that belongs to the current thread. If hWnd is INVALID_HANDLE_VALUE, PeekMessage retrieves messages whose hWnd value is NULL, as posted by the PostThreadMessage function.
----------------------------------------
只说是当前线程（current thread），没有说是整个应用程序。不知道你在哪儿看的？