问题
Things were working fine for both my Android and iOS versions of the app, then I updated VS2019 to 16.1.2 which brought along Xamarin 16.1
I can move forward in the app and it seems that all is well, but when I move backward (one step or PopToRoot), the Element is null in the AdMobViewRenderer. Any ideas?
I am using Xamarin.Firebase.iOS.Admob 7.27.0.3 because that is the one version that would work properly without error.
In anticipation of the "update" reply, I updated to the latest AdMob version and came up with the previously experienced "native linking failed" errors. I backed down one release number at a time (with clean and clearing of cache directory) and reduced the number of errors from over 60 to 59. The only way to eliminate the errors was to go back to 7.27.0.3
Then I opened the project on VS2019 on my mac and the experience was even worse with the inability to compile with any of the admob version numbers between the latest and 7.27.0.3.
I also get a message that the version of mono (latest update for mac) may not be compatible with my windows version when connecting to the mac. As far as I can tell, VS2019 on Win is completely updated.
Any ideas or suggestions to get Admob working for iOS so that I can build and distribute? Android works fine.
回答1:
Well, since nobody answered this question, Microsoft did. They issued another update for Visual Studio 2019 (.3) and that fixed the Admob problem on iOS. What it still hasn't fixed is the problem that element is null every time the location progresses back in the stack. Would anyone have a suggestion for that problem? And the null element has finally been resolved. I had to replace the old Admob plugin with the MarcTron Admob plugin. Not only did this resolve the element issue with iOS, it also solved the need to manually flip between the iOS and Android adunit IDs. Excellent job, MarcTron!
来源：https://stackoverflow.com/questions/56541022/xamarin-forms-ios-admobviewrenderer-vs2019