Convert Viewport point to container reference point in WPF

I have plotted controls on ViewPort at specified locations. And the ViewPort is placed on Canvas. On click on the plotted control, I want to get the coordinate point with reference to the ViewPort container(Canvas). I get the point coordinate where the control place开发者_如何转开发d on ViewPot, but I want it with reference to the container.

Please suggest your ideas for converting the ViewPort Point to normal screen point.

Thanks in advance.

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At last I got:

var currentPosition = Mouse.GetPosition(container);

This will return current click point with reference to ViewPort.