MFC UI线程中的进度栏​​被阻止

Question

对于正在工作的MFC项目，我必须在单独的UI线程（CWinThread）中创建进度栏对话框（CProgressCtrl）。 我从网站http://adilevin.wordpress.com/2009/06/29/user-interface-threads-in-mfc/中获取了示例。 它可以独立工作。 （基本上，它有两个进度条，一个来自主gui线程，一个在单独的ui线程中创建。该示例演示了在主gui线程中执行的计算不会干扰ui线程中创建的进度条）

但是，当我将代码放入应用程序中时，进度条卡在了对CProgressCtrl的SetPos调用中。 当我冻结主线程（运行计算时）时，我从Visual Studio收到消息

该进程似乎已死锁（或未运行任何用户模式代码）。 所有线程均已停止。

所以似乎UI线程正在等待主线程发出的信号？ 但我不知道它在等待什么。 这是卡住的ui线程的调用堆栈。

user32.dll!GetPropW()  + 0x72 bytes 
[Frames below may be incorrect and/or missing, no symbols loaded for user32.dll]    
user32.dll!SendMessageW()  + 0x4c bytes 
uxtheme.dll!DrawThemeParentBackgroundEx()  + 0x114 bytes    
comctl32.dll!GetEffectiveClientRect()  + 0x28f0 bytes   
comctl32.dll!GetEffectiveClientRect()  + 0x2916 bytes   
comctl32.dll!GetEffectiveClientRect()  + 0x2af3 bytes   
comctl32.dll!GetEffectiveClientRect()  + 0x2a25 bytes   
comctl32.dll!GetEffectiveClientRect()  + 0x2992 bytes   
user32.dll!gapfnScSendMessage()  + 0x270 bytes  
user32.dll!gapfnScSendMessage()  + 0x922 bytes  
user32.dll!FillRect()  + 0x110 bytes    
user32.dll!CallWindowProcA()  + 0x1b bytes  
mfc100d.dll!CWnd::DefWindowProcA(unsigned int nMsg=15, unsigned int wParam=0, long lParam=0)  Line 1089 + 0x20 bytes    C++
mfc100d.dll!CWnd::WindowProc(unsigned int message=15, unsigned int wParam=0, long lParam=0)  Line 2088 + 0x1c bytes C++
mfc100d.dll!AfxCallWndProc(CWnd * pWnd=0x08156d68, HWND__ * hWnd=0x00012452, unsigned int nMsg=15, unsigned int wParam=0, long lParam=0)  Line 257 + 0x1c bytes C++
mfc100d.dll!AfxWndProc(HWND__ * hWnd=0x00012452, unsigned int nMsg=15, unsigned int wParam=0, long lParam=0)  Line 420  C++
cv32.dll!AfxWndProcDllStatic(HWND__ * hWnd=0x00012452, unsigned int nMsg=15, unsigned int wParam=0, long lParam=0)  Line 54 + 0x15 bytes    C++
user32.dll!gapfnScSendMessage()  + 0x270 bytes  
user32.dll!GetDC()  + 0x52 bytes    
user32.dll!GetWindowLongW()  + 0x18a bytes  
user32.dll!GetDC()  + 0xab bytes    
ntdll.dll!KiUserCallbackDispatcher()  + 0x2e bytes  
comctl32.dll!GetEffectiveClientRect()  + 0x2660 bytes   
comctl32.dll!RegisterClassNameW()  + 0x37e bytes    
user32.dll!gapfnScSendMessage()  + 0x270 bytes  
user32.dll!gapfnScSendMessage()  + 0x922 bytes  
user32.dll!FillRect()  + 0x110 bytes    
user32.dll!CallWindowProcA()  + 0x1b bytes  
mfc100d.dll!CWnd::DefWindowProcA(unsigned int nMsg=1026, unsigned int wParam=65, long lParam=0)  Line 1089 + 0x20 bytes C++
mfc100d.dll!CWnd::WindowProc(unsigned int message=1026, unsigned int wParam=65, long lParam=0)  Line 2088 + 0x1c bytes  C++
mfc100d.dll!AfxCallWndProc(CWnd * pWnd=0x08156d68, HWND__ * hWnd=0x00012452, unsigned int nMsg=1026, unsigned int wParam=65, long lParam=0)  Line 257 + 0x1c bytes  C++
mfc100d.dll!AfxWndProc(HWND__ * hWnd=0x00012452, unsigned int nMsg=1026, unsigned int wParam=65, long lParam=0)  Line 420   C++
cv32.dll!AfxWndProcDllStatic(HWND__ * hWnd=0x00012452, unsigned int nMsg=1026, unsigned int wParam=65, long lParam=0)  Line 54 + 0x15 bytes C++
user32.dll!gapfnScSendMessage()  + 0x270 bytes  
user32.dll!gapfnScSendMessage()  + 0x922 bytes  
user32.dll!GetWindow()  + 0x21a bytes   
user32.dll!SendMessageA()  + 0x4c bytes 
mfc100d.dll!CProgressCtrl::SetPos(int nPos=65)  Line 363 + 0x46 bytes   C++
cv32.dll!CProgressCtrlWithTimer::OnTimer(unsigned int nIDEvent=1)  Line 1577    C++

有人对哪里出问题有任何线索吗？

当我独自运行示例应用程序时，它不会调用uxtheme.dll，因为示例中未使用它。 最后一个SendMessageW可能是问题吗？

Answer 1

SetPos意味着对SendMessage的调用是阻塞调用。 您绝不能在线程边界上调用SendMessage ，因为它注定会导致死锁。

如果需要更新在主线程上运行的GUI，则必须使用PostMessage ：

PostMessage(hWndMain, UWM_MYMESSAGE, progress, 0);

并在主线程中处理消息：

LRESULT OnMyMessage(WPARAM wParam, LPARAM lParam)
{
   m_progress.SetPos((int)wParam);
   return 1;
}