Help me how to drag on images while zooming in

Question

'm had trying to a lot of code and now I just get a problem while zooming in that can't drag to that see full content of images....
To know get some informations. Here link MSDN for my question
https://social.msdn.microsoft.com/Forums/windowsapps/en-US/6a60dd6c-f2d7-4726-a318-6adc37286f40/thanks-rob-caplan-msft-for-your-code-and-i-asked-some-questioni-hope-everyone-that-help-me?forum=wpdevelop

or

https://social.msdn.microsoft.com/Forums/windowsapps/en-US/f4ca9c96-8787-4f8a-9f72-dbf990093a30/help-me-i-got-a-problem-when-drag-these-picture-while-zoomlimit-it?forum=wpdevelop