DispatchMessage - synchronous or asynchronous

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DispatchMessage is synchronous function.
下面是两个例子，用于说明为什么是同步的：给人异步的错觉，是因为唤起了一个新的消息循环

while (GetMessage (&msg, NULL, 0, 0))  {         if (! TranslateAccelerator (msg.hwnd, hAccelTable, &msg))          {             TranslateMessage (&msg);             DispatchMessage (&msg);         }}//case 1：LRESULT CALLBACK WndProc (HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam) {    int wmId, wmEvent;    switch (message)       {        case WM_COMMAND:             break;        case WM_MOUSEMOVE:        //MessageBox organizes the message loop            MessageBox (NULL, "aa", "aa", MB_OK);             ExitProcess (1);             break;        case WM_DESTROY:             PostQuitMessage (0);             break;        default:             return DefWindowProc (hWnd, message, wParam, lParam);      }   return 0; }//case 2：LRESULT CALLBACK WndProc (HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam) {    int wmId, wmEvent;    switch (message)       {        case WM_COMMAND:             break;        case WM_MOUSEMOVE:             Sleep (INFINITE);             DebugBreak ();            break;        case WM_DESTROY:             PostQuitMessage (0);             break;        default:             return DefWindowProc (hWnd, message, wParam, lParam);      }   return 0; }

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