c# - Xamarin.Forms 不编译 Android 项目

Question

同样，在 Mac 上更新到 VS 8.9.1 后，我在尝试编译我的 Android 项目时遇到了这个错误:

    /Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Tooling.targets(5,5): Error XARSD7023: System.IO.DirectoryNotFoundException: Could not find a part of the path '/Users/giulioserra/Library/Android/sdk'.
  at System.IO.Enumeration.FileSystemEnumerator`1[TResult].CreateDirectoryHandle (System.String path, System.Boolean ignoreNotFound) [0x00032] in <36514b14425c4337b446653c547aa9c3>:0 
  at System.IO.Enumeration.FileSystemEnumerator`1[TResult]..ctor (System.String directory, System.IO.EnumerationOptions options) [0x00048] in <36514b14425c4337b446653c547aa9c3>:0 
  at System.IO.Enumeration.FileSystemEnumerable`1+DelegateEnumerator[TResult]..ctor (System.IO.Enumeration.FileSystemEnumerable`1[TResult] enumerable) [0x00000] in <36514b14425c4337b446653c547aa9c3>:0 
  at System.IO.Enumeration.FileSystemEnumerable`1[TResult]..ctor (System.String directory, System.IO.Enumeration.FileSystemEnumerable`1+FindTransform[TResult] transform, System.IO.EnumerationOptions options) [0x00042] in <36514b14425c4337b446653c547aa9c3>:0 
  at System.IO.Enumeration.FileSystemEnumerableFactory.UserDirectories (System.String directory, System.String expression, System.IO.EnumerationOptions options) [0x00014] in /Users/builder/jenkins/workspace/build-package-osx-mono/2020-02/external/bockbuild/builds/mono-x64/external/corefx/src/System.IO.FileSystem/src/System/IO/Enumeration/FileSystemEnumerableFactory.cs:104 
  at System.IO.Directory.InternalEnumeratePaths (System.String path, System.String searchPattern, System.IO.SearchTarget searchTarget, System.IO.EnumerationOptions options) [0x00045] in /Users/builder/jenkins/workspace/build-package-osx-mono/2020-02/external/bockbuild/builds/mono-x64/external/corefx/src/System.IO.FileSystem/src/System/IO/Directory.cs:180 
  at System.IO.Directory.EnumerateDirectories (System.String path, System.String searchPattern, System.IO.EnumerationOptions enumerationOptions) [0x00000] in /Users/builder/jenkins/workspace/build-package-osx-mono/2020-02/external/bockbuild/builds/mono-x64/external/corefx/src/System.IO.FileSystem/src/System/IO/Directory.cs:196 
  at System.IO.Directory.EnumerateDirectories (System.String path, System.String searchPattern, System.IO.SearchOption searchOption) [0x00000] in /Users/builder/jenkins/workspace/build-package-osx-mono/2020-02/external/bockbuild/builds/mono-x64/external/corefx/src/System.IO.FileSystem/src/System/IO/Directory.cs:193 
  at Xamarin.Android.Tools.AndroidSdkBase.FindBestNDK (System.String androidSdkPath) [0x00038] in /Users/builder/azdo/_work/278/s/xamarin-android/external/xamarin-android-tools/src/Xamarin.Android.Tools.AndroidSdk/Sdks/AndroidSdkBase.cs:172 
  at Xamarin.Android.Tools.AndroidSdkBase+<GetAllAvailableAndroidNdks>d__73.MoveNext () [0x000d0] in /Users/builder/azdo/_work/278/s/xamarin-android/external/xamarin-android-tools/src/Xamarin.Android.Tools.AndroidSdk/Sdks/AndroidSdkBase.cs:164 
  at Xamarin.Android.Tools.AndroidSdkBase.GetValidNdkPath (System.String ctorParam) [0x00068] in /Users/builder/azdo/_work/278/s/xamarin-android/external/xamarin-android-tools/src/Xamarin.Android.Tools.AndroidSdk/Sdks/AndroidSdkBase.cs:128 
  at Xamarin.Android.Tools.AndroidSdkBase.Initialize (System.String androidSdkPath, System.String androidNdkPath, System.String javaSdkPath) [0x00061] in /Users/builder/azdo/_work/278/s/xamarin-android/external/xamarin-android-tools/src/Xamarin.Android.Tools.AndroidSdk/Sdks/AndroidSdkBase.cs:71 
  at Xamarin.Android.Tools.AndroidSdkInfo..ctor (System.Action`2[T1,T2] logger, System.String androidSdkPath, System.String androidNdkPath, System.String javaSdkPath) [0x00025] in /Users/builder/azdo/_work/278/s/xamarin-android/external/xamarin-android-tools/src/Xamarin.Android.Tools.AndroidSdk/AndroidSdkInfo.cs:18 
  at Xamarin.Android.Tasks.MonoAndroidHelper.RefreshAndroidSdk (System.String sdkPath, System.String ndkPath, System.String javaPath, Microsoft.Build.Utilities.TaskLoggingHelper logHelper) [0x00005] in <e0b267300cf54583bbaa8d3ab5dc4081>:0 
  at Xamarin.Android.Tasks.ResolveSdks.RunTask () [0x000ac] in <e0b267300cf54583bbaa8d3ab5dc4081>:0 
  at Xamarin.Android.Tasks.AndroidTask.Execute () [0x00000] in <e0b267300cf54583bbaa8d3ab5dc4081>:0  (XARSD7023) (HangoverBusiness.Android)

我试图删除 bin 和 obj 文件但没有，这个问题只出现在 Android 项目中，而 IOS 版本工作正常。
环境:
Mac OS 卡特琳娜
VS 8.9.1
有什么提示吗？

Answer 1

现在在预发行版中添加了解决方法。
https://docs.microsoft.com/en-us/visualstudio/releasenotes/vs2019-mac-preview-relnotes
解决方法:- 在某些情况下，Android 项目可能无法构建并出现错误找不到 Java SDK，请在 Xamarin.Android SDK 设置面板中设置它的路径。一种解决方法是在终端中执行以下命令:

mkdir -p ~/Library/Android/sdk