GetMessage / PeekMessage - 删除消息队列中的所有消息

时间:2017-04-05 05:39:24

标签: c++ message-queue sendmessage peekmessage

我有以下代码

SendApp,当点击按钮[X]时,执行以下代码

HWND pHWndReceiveApp = FindWindowA(NULL, "ReceiveApp");
    if (NULL == pHWndReceiveApp)
    {
        MessageBox(0, MSG_FAIL, CAPTION, 0);
        return;
    }
    for (int i = 0; i < 7; i++)
    {
        PostMessageA(pHWndReceiveApp, 9, 9, 0);
    }
    MessageBox(0, MSG_OK, CAPTION, 0);

ReceiveApp,这只是一个接收SendApp消息的应用

int i = 0;
msg.message = 69;
while (WM_QUIT != msg.message)
{
    if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE) > 0)
    {
        if (msg.message == 9)
        {
            //I want to remove all messages in the message queue before increase i
            ++i;
            Sleep(1000);
        }

        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
}

正如您所看到的,我希望在ReceiveApp中增加变量i之前删除消息队列中的所有消息。 我看了this article并看到了

  

PM_REMOVE - 处理后,消息将从队列中删除   的PeekMessage。

我认为应该删除所有邮件,但是他们没有,在SendApp中按下按钮[X]后,ReceiveApp中的变量i仍然增加了7。

那么如何删除邮件队列中的所有邮件?

1 个答案:

答案 0 :(得分:0)

我明白了。我们可以在while循环中使用PeekMessage来清除队列中的消息,如下所示

#define ID 9
//...
int i = 0;
msg.message = 69;

while (GetMessage(&msg, 0, 0, 0))
{
    if (msg.message == ID)
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
        while (PeekMessage(&msg, NULL, ID, ID, PM_REMOVE) > 0) //Clear message queue!
        {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
        //I want to remove all message in the message queue before increase i
        ++i;
        Sleep(1000);
    }
}