title: Unresolved external symbol vftable c++
body: <p>I am using visual studio 2008 in my MFC + vtk project. There I am getting a linking error as below:</p>
  
  <blockquote>
    <p>vtkPBFEAView.obj : warning LNK4217: locally defined symbol ?DrawDC@vtkMFCWindow@@QAEXPAVCDC@@@Z (public: void __thiscall vtkMFCWindow::DrawDC(class CDC *)) imported in function "protected: virtual void __thiscall CvtkPBFEAView::OnDraw(class CDC *)" (?OnDraw@CvtkPBFEAView@@MAEXPAVCDC@@@Z)</p>
    
    <p>1>vtkMDIView.obj : warning LNK4049: locally defined symbol ?DrawDC@vtkMFCWindow@@QAEXPAVCDC@@@Z (public: void __thiscall vtkMFCWindow::DrawDC(class CDC *)) imported
    1>vtkPBFEAView.obj : warning LNK4217: locally defined symbol ??0vtkMFCWindow@@QAE@PAVCWnd@@@Z (public: __thiscall vtkMFCWindow::vtkMFCWindow(class CWnd *)) imported in function "public: void __thiscall vtkPBFEAViewImpl::initialize(class CWnd *)" (?initialize@vtkPBFEAViewImpl@@QAEXPAVCWnd@@@Z)</p>
    
    <p>1>vtkMDIView.obj : warning LNK4049: locally defined symbol ??0vtkMFCWindow@@QAE@PAVCWnd@@@Z (public: __thiscall vtkMFCWindow::vtkMFCWindow(class CWnd *)) imported
    1>vtkPBFEAView.obj : warning LNK4217: locally defined symbol ??1vtkMFCWindow@@UAE@XZ (public: virtual __thiscall vtkMFCWindow::~vtkMFCWindow(void)) imported in function "public: virtual void * __thiscall vtkMFCWindow::`scalar deleting destructor'(unsigned int)" (??_GvtkMFCWindow@@UAEPAXI@Z)</p>
    
    <p>1>vtkMDIView.obj : warning LNK4217: locally defined symbol ??1vtkMFCWindow@@UAE@XZ (public: virtual __thiscall vtkMFCWindow::~vtkMFCWindow(void)) imported in function "public: void __thiscall vtkMDIViewImpl::adjust_contours(int,double,double)" (?adjust_contours@vtkMDIViewImpl@@QAEXHNN@Z)</p>
    
    <p>1>vtkMFCWindow.obj : error LNK2019: unresolved external symbol "_<em>declspec(dllimport) const vtkMFCWindow::`vftable'" (</em>_imp_??_7vtkMFCWindow@@6B@) referenced in function "public: __thiscall vtkMFCWindow::vtkMFCWindow(class CWnd *)" (??0vtkMFCWindow@@QAE@PAVCWnd@@@Z)</p>
  </blockquote>
  
  <p>Can anyone explain me the reason for this error?</p>
  
  <p>Thanks in advance.</p>