MFC UI線程中的進度欄​​被阻止

Question

對於正在工作的MFC項目，我必須在單獨的UI線程（CWinThread）中創建進度欄對話框（CProgressCtrl）。 我從網站http://adilevin.wordpress.com/2009/06/29/user-interface-threads-in-mfc/中獲取了示例。 它可以獨立工作。 （基本上，它有兩個進度條，一個來自主gui線程，一個在單獨的ui線程中創建。該示例演示了在主gui線程中執行的計算不會干擾ui線程中創建的進度條）

但是，當我將代碼放入應用程序中時，進度條卡在了對CProgressCtrl的SetPos調用中。 當我凍結主線程（運行計算時）時，我從Visual Studio收到消息

該進程似乎已死鎖（或未運行任何用戶模式代碼）。 所有線程均已停止。

所以似乎UI線程正在等待主線程發出的信號？ 但我不知道它在等待什么。 這是卡住的ui線程的調用堆棧。

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++

有人對哪里出問題有任何線索嗎？

當我獨自運行示例應用程序時，它不會調用uxtheme.dll，因為示例中未使用它。 最后一個SendMessageW可能是問題嗎？

Answer 1

SetPos意味着對SendMessage的調用是阻塞調用。 您絕不能在線程邊界上調用SendMessage ，因為它注定會導致死鎖。

如果需要更新在主線程上運行的GUI，則必須使用PostMessage ：

PostMessage(hWndMain, UWM_MYMESSAGE, progress, 0);

並在主線程中處理消息：

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