@Claude31 thanks for your response! My main problem is that XCode does not allow me to do the step in your "Create a UIView": "Define the constraints with respect to the scrollView (Superview)" . I.e. I am able to set constraints for the scroll view, but cannot set any constraints for the image view inside the scroll view. Please see attached screen shot of my current constraints list of the scroll view.

To clarify 2 things, (1) I was able to set constraints between the scroll view and its superview, i.e. the Content View of the cell. (2) Xcode was not able to fix the "missing constraints" automatically, I tried that.

Sorry about my late response. I am trying to use iPhone to communicate with other devices in the same WiFi LAN, and wondering if can use TDLS to reduce the load on the WiFi router. If not TDLS, is there any other thing I can use for iPhone to achieve the goal? Thanks.