[VTK]为什么这个程序不能显示mha文件呢

vtk 7.1if (argc < 2)
{
std::cout<<argv[0]<<" "<<"ImageFile(*.mhd)"<<std::endl;
return EXIT_FAILURE;
}
vtkSmartPointer<vtkMetaImageReader> reader =
vtkSmartPointer<vtkMetaImageReader>::New();
reader->SetFileName(argv[1]);
reader->Update(); int extent[6];
double spacing[3];
double origin[3]; reader->GetOutput()->GetExtent(extent);
reader->GetOutput()->GetSpacing(spacing);
reader->GetOutput()->GetOrigin(origin); double center[3];
center[0] = origin[0] + spacing[0] * 0.5 * (extent[0] + extent[1]);
center[1] = origin[1] + spacing[1] * 0.5 * (extent[2] + extent[3]);
center[2] = origin[2] + spacing[2] * 0.5 * (extent[4] + extent[5]); static double axialElements[16] = {
1, 0, 0, 0,
0, 1, 0, 0,
0, 0, 1, 0,
0, 0, 0, 1 
}; vtkSmartPointer<vtkMatrix4x4> resliceAxes =
vtkSmartPointer<vtkMatrix4x4>::New();
resliceAxes->DeepCopy(axialElements);
resliceAxes->SetElement(0, 3, center[0]);
resliceAxes->SetElement(1, 3, center[1]);
resliceAxes->SetElement(2, 3, center[2]); vtkSmartPointer<vtkImageReslice> reslice =
vtkSmartPointer<vtkImageReslice>::New();
reslice->SetInputConnection(reader->GetOutputPort());
reslice->SetOutputDimensionality(2);
reslice->SetResliceAxes(resliceAxes);
reslice->SetInterpolationModeToLinear(); vtkSmartPointer<vtkLookupTable> colorTable =
vtkSmartPointer<vtkLookupTable>::New();
colorTable->SetRange(0, 1000); 
colorTable->SetValueRange(0.0, 1.0);
colorTable->SetSaturationRange(0.0, 0.0);
colorTable->SetRampToLinear();
colorTable->Build(); vtkSmartPointer<vtkImageMapToColors> colorMap =
vtkSmartPointer<vtkImageMapToColors>::New();
colorMap->SetLookupTable(colorTable);
colorMap->SetInputConnection(reslice->GetOutputPort()); vtkSmartPointer<vtkImageActor> imgActor =
vtkSmartPointer<vtkImageActor>::New();
imgActor->SetInputData(colorMap->GetOutput()); vtkSmartPointer<vtkRenderer> renderer =
vtkSmartPointer<vtkRenderer>::New();
renderer->AddActor(imgActor);
renderer->SetBackground(1.0, 1.0, 1.0); vtkSmartPointer<vtkRenderWindow> renderWindow =
vtkSmartPointer<vtkRenderWindow>::New();
renderWindow->AddRenderer(renderer);
renderWindow->Render();
renderWindow->SetSize(640, 480);
renderWindow->SetWindowName("ImageResliceExample"); vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
vtkSmartPointer<vtkRenderWindowInteractor>::New();
vtkSmartPointer<vtkInteractorStyleImage> imagestyle =
vtkSmartPointer<vtkInteractorStyleImage>::New(); renderWindowInteractor->SetInteractorStyle(imagestyle);
renderWindowInteractor->SetRenderWindow(renderWindow);
renderWindowInteractor->Initialize();
renderWindowInteractor->Start(); return EXIT_SUCCESS;结果没有报错，也没有显示图形