如何修复更新到 Visual studio 2019 版本 16.7.0 后出现的错误

Question

我有一个使用Xamarin.Forms构建的移动应用程序

将 Visual Studio 从16.4.4更新到16.7.0后

出现了这些错误

Assembly 'Xamarin.GooglePlayServices.Maps' is using '[assembly: Java.Interop.JavaLibraryReferenceAttribute]', which is no longer supported. Use a newer version of this NuGet package or notify the library author. MyApp.Android           
Assembly 'Xamarin.Android.Support.v7.CardView' is using '[assembly: Android.IncludeAndroidResourcesFromAttribute]', which is no longer supported. Use a newer version of this NuGet package or notify the library author.   MyApp.Android           
Assembly 'Xamarin.GooglePlayServices.Base' is using '[assembly: Android.IncludeAndroidResourcesFromAttribute]', which is no longer supported. Use a newer version of this NuGet package or notify the library author.   MyApp.Android           
Assembly 'Xamarin.Android.Support.v7.MediaRouter' is using '[assembly: Java.Interop.JavaLibraryReferenceAttribute]', which is no longer supported. Use a newer version of this NuGet package or notify the library author.  MyApp.Android           
Assembly 'Xamarin.Android.Support.Vector.Drawable' is using '[assembly: Java.Interop.JavaLibraryReferenceAttribute]', which is no longer supported. Use a newer version of this NuGet package or notify the library author. MyApp.Android           
Assembly 'Xamarin.Android.Support.Design' is using '[assembly: Android.IncludeAndroidResourcesFromAttribute]', which is no longer supported. Use a newer version of this NuGet package or notify the library author.    MyApp.Android           
Assembly 'Xamarin.GooglePlayServices.Gcm' is using '[assembly: Java.Interop.JavaLibraryReferenceAttribute]', which is no longer supported. Use a newer version of this NuGet package or notify the library author.  MyApp.Android           
Assembly 'Xamarin.Android.Support.v7.AppCompat' is using '[assembly: Java.Interop.JavaLibraryReferenceAttribute]', which is no longer supported. Use a newer version of this NuGet package or notify the library author.    MyApp.Android           
Assembly 'Xamarin.Android.Support.v7.RecyclerView' is using '[assembly: Java.Interop.JavaLibraryReferenceAttribute]', which is no longer supported. Use a newer version of this NuGet package or notify the library author. MyApp.Android           
Assembly 'Xamarin.GooglePlayServices.Basement' is using '[assembly: Android.IncludeAndroidResourcesFromAttribute]', which is no longer supported. Use a newer version of this NuGet package or notify the library author.   MyApp.Android           
Assembly 'Xamarin.Android.Support.Animated.Vector.Drawable' is using '[assembly: Java.Interop.JavaLibraryReferenceAttribute]', which is no longer supported. Use a newer version of this NuGet package or notify the library author.    MyApp.Android           
Assembly 'Xamarin.Android.Support.v7.AppCompat' is using '[assembly: Android.IncludeAndroidResourcesFromAttribute]', which is no longer supported. Use a newer version of this NuGet package or notify the library author.  MyApp.Android           
Assembly 'Xamarin.GooglePlayServices.Maps' is using '[assembly: Android.IncludeAndroidResourcesFromAttribute]', which is no longer supported. Use a newer version of this NuGet package or notify the library author.   MyApp.Android           
Assembly 'Xamarin.Android.Support.v4' is using '[assembly: Java.Interop.JavaLibraryReferenceAttribute]', which is no longer supported. Use a newer version of this NuGet package or notify the library author.  MyApp.Android           
Assembly 'Xamarin.Android.Support.v7.CardView' is using '[assembly: Java.Interop.JavaLibraryReferenceAttribute]', which is no longer supported. Use a newer version of this NuGet package or notify the library author. MyApp.Android           
Assembly 'Xamarin.Android.Support.v4' is using '[assembly: Java.Interop.JavaLibraryReferenceAttribute]', which is no longer supported. Use a newer version of this NuGet package or notify the library author.  MyApp.Android           
Assembly 'Xamarin.GooglePlayServices.Gcm' is using '[assembly: Android.IncludeAndroidResourcesFromAttribute]', which is no longer supported. Use a newer version of this NuGet package or notify the library author.    MyApp.Android           
Assembly 'Xamarin.Android.Support.v7.RecyclerView' is using '[assembly: Android.IncludeAndroidResourcesFromAttribute]', which is no longer supported. Use a newer version of this NuGet package or notify the library author.   MyApp.Android           
Assembly 'Xamarin.Android.Support.Design' is using '[assembly: Java.Interop.JavaLibraryReferenceAttribute]', which is no longer supported. Use a newer version of this NuGet package or notify the library author.  MyApp.Android           
Assembly 'Xamarin.Android.Support.v7.MediaRouter' is using '[assembly: Java.Interop.JavaLibraryReferenceAttribute]', which is no longer supported. Use a newer version of this NuGet package or notify the library author.  MyApp.Android           
Assembly 'Xamarin.Android.Support.Animated.Vector.Drawable' is using '[assembly: Android.IncludeAndroidResourcesFromAttribute]', which is no longer supported. Use a newer version of this NuGet package or notify the library author.  MyApp.Android           
Assembly 'Xamarin.Android.Support.Vector.Drawable' is using '[assembly: Android.IncludeAndroidResourcesFromAttribute]', which is no longer supported. Use a newer version of this NuGet package or notify the library author.   MyApp.Android           
Assembly 'Xamarin.GooglePlayServices.Base' is using '[assembly: Java.Interop.JavaLibraryReferenceAttribute]', which is no longer supported. Use a newer version of this NuGet package or notify the library author. MyApp.Android           
Assembly 'Xamarin.Android.Support.v7.MediaRouter' is using '[assembly: Android.IncludeAndroidResourcesFromAttribute]', which is no longer supported. Use a newer version of this NuGet package or notify the library author.    MyApp.Android           
Assembly 'Xamarin.Android.Support.v4' is using '[assembly: Android.IncludeAndroidResourcesFromAttribute]', which is no longer supported. Use a newer version of this NuGet package or notify the library author.    MyApp.Android           
Assembly 'Xamarin.GooglePlayServices.Basement' is using '[assembly: Java.Interop.JavaLibraryReferenceAttribute]', which is no longer supported. Use a newer version of this NuGet package or notify the library author. MyApp.Android       

我已经尝试过什么？

1-我尝试删除bin和obj文件夹以强制项目重建所有内容，但错误仍然出现

2-我尝试降级到16.4.4并且错误消失了，但我不想通过这种方式修复它，因为我想使用16.7.0 中的这个新功能创建一个新的其他应用程序

那么，有没有办法在不降级到旧版本的情况下消除这些错误呢？

笔记：

Xamarin.Forms的版本是2.3

Answer 1

Xamarin.Forms的版本是2.3

您需要更新较新版本的 Xamarin.Forms，因为 Visual Studio 2019 不支持 v2.3；Xamarin.Forms v2.3于 2016 年发布。

我建议使用最新版本的 Xamarin.Forms。