0
我已经继承了当前正在从其CView::OnBeginPrinting重写中查询ADODB数据库的程序的维护。但是，当ADODB数据库句柄是进程外数据库连接的代理时，它经常崩溃 - 显然，在等待RPC响应时，绘制消息导致它重新输入CView的呈现处理，导致事情变得非常困惑。在CView中使用COM RPC :: OnBeginPrinting
有没有一种方法可以安全地使用来自CView::OnBeginPrinting的过程对象的COM？例如，如果我能阻止窗口消息有问题的窗口，直到COM调用完成，这可能会工作...
这里就是断言发生的堆栈跟踪：
mfc100d.dll!CPreviewDC::ReleaseOutputDC() Line 138 C++ (asserts here)
mfc100d.dll!CPreviewView::OnDraw(CDC * pDC) Line 801 C++
mfc100d.dll!CView::OnPaint() Line 189 C++
mfc100d.dll!CWnd::OnWndMsg(unsigned int message, unsigned int wParam, long lParam, long * pResult) Line 2354 C++
mfc100d.dll!CWnd::WindowProc(unsigned int message, unsigned int wParam, long lParam) Line 2067 + 0x20 bytes C++
mfc100d.dll!AfxCallWndProc(CWnd * pWnd, HWND__ * hWnd, unsigned int nMsg, unsigned int wParam, long lParam) Line 248 + 0x1c bytes C++
mfc100d.dll!AfxWndProc(HWND__ * hWnd, unsigned int nMsg, unsigned int wParam, long lParam) Line 411 C++
mfc100d.dll!AfxWndProcBase(HWND__ * hWnd, unsigned int nMsg, unsigned int wParam, long lParam) Line 420 + 0x15 bytes C++
[email protected]() + 0x28 bytes
[email protected]() + 0xa2 bytes
[email protected]() + 0x4b bytes
[email protected]() + 0x24 bytes
[email protected]() + 0x2e bytes
[email protected]() + 0xc bytes
[email protected]() + 0xf bytes
mfc100d.dll!COleMessageFilter::OnMessagePending(const tagMSG * __formal) Line 114 C++
mfc100d.dll!COleMessageFilter::XMessageFilter::MessagePending(HTASK__ * htaskCallee, unsigned long dwTickCount, unsigned long __formal) Line 312 C++
ole32.dll!CCliModalLoop::HandlePendingMessage() + 0x91de bytes
ole32.dll!CCliModalLoop::HandleWakeForMsg() + 0x46 bytes
ole32.dll!CCliModalLoop::BlockFn() - 0x34d92 bytes
ole32.dll!ModalLoop() + 0x5b bytes
ole32.dll!ThreadSendReceive() + 0x36c bytes
ole32.dll!CRpcChannelBuffer::SwitchAptAndDispatchCall() + 0x4d bytes
ole32.dll!CRpcChannelBuffer::SendReceive2() + 0x8d bytes
ole32.dll!CCliModalLoop::SendReceive() + 0x1e bytes
ole32.dll!CAptRpcChnl::SendReceive() + 0x1a25 bytes
ole32.dll!CCtxComChnl::SendReceive() + 0x47 bytes
[email protected]() + 0x40 bytes
rpcrt4.dll!_NdrClientCall2() - 0xa83 bytes
[email protected]() + 0x5d bytes
[email protected]() + 0xf bytes
ole32.dll!CStdMarshal::Begin_RemQIAndUnmarshal1() + 0x91 bytes
ole32.dll!CStdMarshal::Begin_QueryRemoteInterfaces() + 0x46 bytes
ole32.dll!CStdMarshal::QueryRemoteInterfaces() + 0x37 bytes
ole32.dll!CStdIdentity::CInternalUnk::QueryMultipleInterfaces() - 0x2adf0 bytes
ole32.dll!CStdIdentity::CInternalUnk::QueryInterface() + 0x30 bytes
[email protected]() + 0x16 bytes
jscript.dll!VAR::SetHeapObject() + 0x31 bytes
jscript.dll!VAR::Import() + 0x45d bytes
jscript.dll!VarList::ImportVar() + 0x2e bytes
jscript.dll!VarList::ImportRgvar() - 0x160fb bytes
jscript.dll!CSession::Execute() + 0xd6 bytes
jscript.dll!NameTbl::InvokeDef() + 0x146 bytes
jscript.dll!NameTbl::InvokeEx() - 0x42f bytes
jscript.dll!IDispatchExInvokeEx2() + 0x8e bytes
jscript.dll!IDispatchExInvokeEx() + 0x4f bytes
jscript.dll!NameTbl::InvokeEx() - 0x18653 bytes
msscript.ocx!CScriptControl::ModuleRun() + 0x171 bytes
msscript.ocx!CScriptControl::Run() + 0x5d bytes
[several levels of my code, which I cannot reveal]
myapp.exe!MyView::OnBeginPrinting(CDC * pDC, CPrintInfo * pInfo) Line 92 C++
mfc100d.dll!CPreviewView::SetPrintView(CView * pPrintView) Line 370 C++
mfc100d.dll!CView::DoPrintPreview(unsigned int nIDResource, CView * pPrintView, CRuntimeClass * pPreviewViewClass, CPrintPreviewState * pState) Line 218 + 0xc bytes C++
mfc100d.dll!AFXPrintPreview(CView * pView) Line 298 + 0x1b bytes C++
您是否真的看到该方法重新进入？ – sharptooth 2010-07-20 08:38:11
'OnBeginPrinting'本身不会被重新输入，但它会进入'CPreviewView :: OnDraw'，然后由于'm_hDC'为空而在'CPreviewDC :: ReleaseOutputDC'中声明。 – bdonlan 2010-07-20 16:18:12