我写了一个简单Win32 App的Visual Studio的2019对10场。在WinMain函数内的主消息循环中，我有：

while (Msg.message != WM_QUIT) {

    if (PeekMessage(&Msg, NULL, 0, 0, PM_REMOVE) > 0) {
        TranslateMessage(&Msg);
        DispatchMessage(&Msg);

        swprintf_s(msgbuf, _T("In the PeekMessage loop cnt: %d, msg: %dn"), loop_cnt++, Msg.message);
        OutputDebugString(msgbuf);
    }
...
}

我得到以下输出：

In the PeekMessage loop cnt: 0, msg: 799
In the PeekMessage loop cnt: 1, msg: 49300
In the PeekMessage loop cnt: 2, msg: 96
In the PeekMessage loop cnt: 3, msg: 96
In the PeekMessage loop cnt: 4, msg: 275
In the PeekMessage loop cnt: 5, msg: 275
...

奇怪的是，消息 id 返回到输出，就像799或49300不存在于 WinUser.h 中！所以我的问题是这些消息是什么以及它来自哪里？

回答