Unfortunately, there is no direct way to query detailed information about the Remote Desktop app environment, including the exact screen coordinates and dimensions of the iOS app bar, from within your .NET WPF client application. The Remote Desktop app environment is managed by the iOS Microsoft Remote Desktop application, and the app bar is part of the iOS app's user interface.
However, there are a few things you can do to work around this issue:
Provide instructions to your users on how to reposition the app bar. You can include instructions in your application's user interface or provide a separate document or video tutorial that explains how to reposition the app bar.
Design your application's user interface to avoid having important controls or navigation elements located in the area of the screen that is likely to be obscured by the app bar. This may require some redesign of your application's user interface, but it can help ensure that your users can always access the controls they need.
Consider using a different remote desktop client application that provides more control over the user interface. There are several remote desktop client applications available for iOS, and some of them may provide more control over the user interface than the Microsoft Remote Desktop application.
Submit a feature request to Microsoft for the ability to query detailed information about the Remote Desktop app environment. Microsoft is always looking for feedback from developers and users, and feature requests can help drive future development efforts.