vktPropPicker->picker report read access violation

I am using both dicomseiral read and pickpixel example.
Well, in my custom imageinteractorstyle I difen OnMouseMove function and code as in pickpixel exmaple.
I got a exception triggered in my Qt debugger as below:

I check the debugger, it seems no nullptr:

The GetEventPosition function can return the right position infomation.
I alse test the below code:


it also return a exception.

Can someone help me?
If you need more debug information, just tell me.

Part of my OnMouseMove function:

void myVtkInteractorStyleImage::OnMouseMove(){
    vtkRenderWindowInteractor* interactor =
    vtkRenderer* renderer = this->_ImageViewer->GetRenderer();
    vtkImageActor* actor = this->_ImageViewer->GetImageActor();
    vtkImageData* image = this->_ImageViewer->GetInput();
    vtkInteractorStyle* style =
    // Pick at the mouse location provided by the interactor
                       interactor->GetEventPosition()[1], 0.0, renderer);

    // There could be other props assigned to this picker, so
    // make sure we picked the image actor
    vtkAssemblyPath* path = this->Picker->GetPath();
    bool validPick = false;