Xamarin和.NET Standard 2 Library问题

Question

我创建了一个跨平台库,它有3个特定于平台的实现:

• Android的
• iOS版
• .NET Standard 2.0

我和Nuget一起打包了这个库,就像跨平台库项目一样.

现在,当我创建一个新的Xamarin Forms项目并选择.NET Standard作为共享代码的方法时,我引用我的nuget并尝试在android模拟器中运行它,我得到:

/Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Common.targets(2,2): Error: Exception while loading assemblies: System.IO.FileNotFoundException: Could not load assembly 'SDK.NetStandard, Version=1.0.0.0, Culture=neutral, PublicKeyToken='. Perhaps it doesn't exist in the Mono for Android profile?
File name: 'SDK.NetStandard.dll'
  at Java.Interop.Tools.Cecil.DirectoryAssemblyResolver.Resolve (Mono.Cecil.AssemblyNameReference reference, Mono.Cecil.ReaderParameters parameters) [0x0009a] in /Users/builder/data/lanes/5945/342b2ce9/source/monodroid/external/xamarin-android/external/Java.Interop/src/Java.Interop.Tools.Cecil/Java.Interop.Tools.Cecil/DirectoryAssemblyResolver.cs:229 
  at Java.Interop.Tools.Cecil.DirectoryAssemblyResolver.Resolve (Mono.Cecil.AssemblyNameReference reference) [0x00000] in /Users/builder/data/lanes/5945/342b2ce9/source/monodroid/external/xamarin-android/external/Java.Interop/src/Java.Interop.Tools.Cecil/Java.Interop.Tools.Cecil/DirectoryAssemblyResolver.cs:179 
  at Xamarin.Android.Tasks.ResolveAssemblies.AddAssemblyReferences (Java.Interop.Tools.Cecil.DirectoryAssemblyResolver resolver, System.Collections.Generic.ICollection`1[T] assemblies, Mono.Cecil.AssemblyDefinition assembly, System.Boolean topLevel) [0x0014a] in <fdfe8f54615a4e2ab24c72dc90da5c64>:0 
  at Xamarin.Android.Tasks.ResolveAssemblies.Execute (Java.Interop.Tools.Cecil.DirectoryAssemblyResolver resolver) [0x00237] in <fdfe8f54615a4e2ab24c72dc90da5c64>:0  (blank.Android)

我已经仔细检查过,nuget包中存在SDK.NetStandard.dll.

我已经通过创建一个带有.NET Core 2的简单控制台应用程序以及那里的库工作属性来测试它.

[编辑]

我已将我的软件包从SDK重命名为Matchmore.SDK以减轻混淆错误在运行时iOS中看起来像这样.

System.IO.FileNotFoundException: Could not load file or assembly 'Matchmore.SDK.NetStandard, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' or one of its dependencies.
  at blankstandard.App..ctor () [0x0001b] in /Users/lmlynik/Projects/blankstandard/blankstandard/App.xaml.cs:15
  at blankstandard.iOS.AppDelegate.FinishedLaunching (UIKit.UIApplication app, Foundation.NSDictionary options) [0x00007] in /Users/lmlynik/Projects/blankstandard/blankstandard.iOS/AppDelegate.cs:26
  at at (wrapper managed-to-native) UIKit.UIApplication.UIApplicationMain(int,string[],intptr,intptr)
  at UIKit.UIApplication.Main (System.String[] args, System.IntPtr principal, System.IntPtr delegate) [0x00005] in /Library/Frameworks/Xamarin.iOS.framework/Versions/11.10.1.178/src/Xamarin.iOS/UIKit/UIApplication.cs:79
  at UIKit.UIApplication.Main (System.String[] args, System.String principalClassName, System.String delegateClassName) [0x0002c] in /Library/Frameworks/Xamarin.iOS.framework/Versions/11.10.1.178/src/Xamarin.iOS/UIKit/UIApplication.cs:63
  at blankstandard.iOS.Application.Main (System.String[] args) [0x00001] in /Users/lmlynik/Projects/blankstandard/blankstandard.iOS/Main.cs:17

在解压缩nupkg后,你可以看到DLL在那里.

Answer 1

您缺少 SDK.NetStandard.dll 文件。转到 Nuget 并安装/更新 NETStandard。库，解决方案 -> 管理解决方案的 Nuget 包。