如何解决 .NET Core 包版本冲突

Question

我正在从一个 .NET MVC 5 Web 应用程序迁移到一个 .NET Core 2.2 Web API 项目以及五个 .NET Standard 2.0 项目，它们都位于一个解决方案下。

我现在收到 28 条关于包冲突的警告 (MSB3277)，它们都在 System 命名空间内。例如，Version=4.0.11.0 和Version=4.0.14.0 之间的System.Collections.Concurrent 似乎存在版本冲突（请参阅下面的错误块）。

已尝试故障排除：

1. 我尝试卸载所有我不使用的 .NET Core SDK，目前安装了2.2.300。那没有用。
2. 我尝试在解决方案级别进入 NuGet 以安装缺少的程序集，但选择列表中甚至没有 4.0.14。我可以从以下版本中进行选择：4.3、4.0.12、4.0.10 和 4.0.0。我确实尝试在所有项目中安装4.3，但没有奏效。
3. Web 上的其他解决方案似乎建议降低 SDK 上的版本或在 *.csproj 文件中硬编码引用 - 如果我不必这样做，我都不喜欢这样做。我不喜欢前者，因为向后移动似乎违反直觉，我不喜欢后者，因为硬编码修复永久使用旧包，这似乎是一个非常糟糕的主意，因为它似乎不太可能更新到发布的新版本。

有谁知道如何解决这些警告？非常感谢任何帮助。

构建时出现警告之一的详细输出：

Line 5419: 3>    Dependency "System.Collections.Concurrent, Version=4.0.14.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a".
Line 5420: 3>        Could not resolve this reference. Could not locate the assembly "System.Collections.Concurrent, Version=4.0.14.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a". Check to make sure the assembly exists on disk. If this reference is required by your code, you may get compilation errors.
Line 5675: 3>    There was a conflict between "System.Collections.Concurrent, Version=4.0.11.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" and "System.Collections.Concurrent, Version=4.0.14.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a".
Line 5675: 3>    There was a conflict between "System.Collections.Concurrent, Version=4.0.11.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" and "System.Collections.Concurrent, Version=4.0.14.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a".
Line 5676: 3>        "System.Collections.Concurrent, Version=4.0.11.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" was chosen because it was primary and "System.Collections.Concurrent, Version=4.0.14.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" was not.
Line 5676: 3>        "System.Collections.Concurrent, Version=4.0.11.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" was chosen because it was primary and "System.Collections.Concurrent, Version=4.0.14.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" was not.
Line 5677: 3>        References which depend on "System.Collections.Concurrent, Version=4.0.11.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" [C:\Program Files\dotnet\sdk\NuGetFallbackFolder\netstandard.library\2.0.3\build\netstandard2.0\ref\System.Collections.Concurrent.dll].
Line 5677: 3>        References which depend on "System.Collections.Concurrent, Version=4.0.11.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" [C:\Program Files\dotnet\sdk\NuGetFallbackFolder\netstandard.library\2.0.3\build\netstandard2.0\ref\System.Collections.Concurrent.dll].

更新

更多疑难解答：

https://github.com/dotnet/standard/issues/731

https://github.com/dotnet/corefx/issues/32561

这是微软的错误吗？

构建列出所有 28 个警告的最小输出：

3>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Current\Bin\Microsoft.Common.CurrentVersion.targets(2106,5): warning MSB3277: Found conflicts between different versions of "System.Collections.Concurrent" that could not be resolved.  These reference conflicts are listed in the build log when log verbosity is set to detailed.
3>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Current\Bin\Microsoft.Common.CurrentVersion.targets(2106,5): warning MSB3277: Found conflicts between different versions of "System.Collections" that could not be resolved.  These reference conflicts are listed in the build log when log verbosity is set to detailed.
3>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Current\Bin\Microsoft.Common.CurrentVersion.targets(2106,5): warning MSB3277: Found conflicts between different versions of "System.Collections.NonGeneric" that could not be resolved.  These reference conflicts are listed in the build log when log verbosity is set to detailed.
3>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Current\Bin\Microsoft.Common.CurrentVersion.targets(2106,5): warning MSB3277: Found conflicts between different versions of "System.ComponentModel" that could not be resolved.  These reference conflicts are listed in the build log when log verbosity is set to detailed.
3>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Current\Bin\Microsoft.Common.CurrentVersion.targets(2106,5): warning MSB3277: Found conflicts between different versions of "System.Diagnostics.Debug" that could not be resolved.  These reference conflicts are listed in the build log when log verbosity is set to detailed.
3>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Current\Bin\Microsoft.Common.CurrentVersion.targets(2106,5): warning MSB3277: Found conflicts between different versions of "System.Diagnostics.Process" that could not be resolved.  These reference conflicts are listed in the build log when log verbosity is set to detailed.
3>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Current\Bin\Microsoft.Common.CurrentVersion.targets(2106,5): warning MSB3277: Found conflicts between different versions of "System.Diagnostics.Tracing" that could not be resolved.  These reference conflicts are listed in the build log when log verbosity is set to detailed.
3>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Current\Bin\Microsoft.Common.CurrentVersion.targets(2106,5): warning MSB3277: Found conflicts between different versions of "System.IO.FileSystem" that could not be resolved.  These reference conflicts are listed in the build log when log verbosity is set to detailed.
3>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Current\Bin\Microsoft.Common.CurrentVersion.targets(2106,5): warning MSB3277: Found conflicts between different versions of "System.Linq" that could not be resolved.  These reference conflicts are listed in the build log when log verbosity is set to detailed.
3>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Current\Bin\Microsoft.Common.CurrentVersion.targets(2106,5): warning MSB3277: Found conflicts between different versions of "System.Net.Primitives" that could not be resolved.  These reference conflicts are listed in the build log when log verbosity is set to detailed.
3>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Current\Bin\Microsoft.Common.CurrentVersion.targets(2106,5): warning MSB3277: Found conflicts between different versions of "System.Net.Security" that could not be resolved.  These reference conflicts are listed in the build log when log verbosity is set to detailed.
3>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Current\Bin\Microsoft.Common.CurrentVersion.targets(2106,5): warning MSB3277: Found conflicts between different versions of "System.Resources.ResourceManager" that could not be resolved.  These reference conflicts are listed in the build log when log verbosity is set to detailed.
3>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Current\Bin\Microsoft.Common.CurrentVersion.targets(2106,5): warning MSB3277: Found conflicts between different versions of "System.Runtime" that could not be resolved.  These reference conflicts are listed in the build log when log verbosity is set to detailed.
3>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Current\Bin\Microsoft.Common.CurrentVersion.targets(2106,5): warning MSB3277: Found conflicts between different versions of "System.Runtime.Extensions" that could not be resolved.  These reference conflicts are listed in the build log when log verbosity is set to detailed.
3>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Current\Bin\Microsoft.Common.CurrentVersion.targets(2106,5): warning MSB3277: Found conflicts between different versions of "System.Runtime.InteropServices.RuntimeInformation" that could not be resolved.  These reference conflicts are listed in the build log when log verbosity is set to detailed.
3>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Current\Bin\Microsoft.Common.CurrentVersion.targets(2106,5): warning MSB3277: Found conflicts between different versions of "System.Security.Cryptography.Algorithms" that could not be resolved.  These reference conflicts are listed in the build log when log verbosity is set to detailed.
3>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Current\Bin\Microsoft.Common.CurrentVersion.targets(2106,5): warning MSB3277: Found conflicts between different versions of "System.Security.Cryptography.Csp" that could not be resolved.  These reference conflicts are listed in the build log when log verbosity is set to detailed.
3>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Current\Bin\Microsoft.Common.CurrentVersion.targets(2106,5): warning MSB3277: Found conflicts between different versions of "System.Security.Cryptography.Encoding" that could not be resolved.  These reference conflicts are listed in the build log when log verbosity is set to detailed.
3>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Current\Bin\Microsoft.Common.CurrentVersion.targets(2106,5): warning MSB3277: Found conflicts between different versions of "System.Security.Cryptography.Primitives" that could not be resolved.  These reference conflicts are listed in the build log when log verbosity is set to detailed.
3>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Current\Bin\Microsoft.Common.CurrentVersion.targets(2106,5): warning MSB3277: Found conflicts between different versions of "System.Security.Cryptography.X509Certificates" that could not be resolved.  These reference conflicts are listed in the build log when log verbosity is set to detailed.
3>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Current\Bin\Microsoft.Common.CurrentVersion.targets(2106,5): warning MSB3277: Found conflicts between different versions of "System.Text.Encoding.Extensions" that could not be resolved.  These reference conflicts are listed in the build log when log verbosity is set to detailed.
3>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Current\Bin\Microsoft.Common.CurrentVersion.targets(2106,5): warning MSB3277: Found conflicts between different versions of "System.Text.RegularExpressions" that could not be resolved.  These reference conflicts are listed in the build log when log verbosity is set to detailed.
3>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Current\Bin\Microsoft.Common.CurrentVersion.targets(2106,5): warning MSB3277: Found conflicts between different versions of "System.Threading" that could not be resolved.  These reference conflicts are listed in the build log when log verbosity is set to detailed.
3>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Current\Bin\Microsoft.Common.CurrentVersion.targets(2106,5): warning MSB3277: Found conflicts between different versions of "System.Threading.Tasks" that could not be resolved.  These reference conflicts are listed in the build log when log verbosity is set to detailed.
3>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Current\Bin\Microsoft.Common.CurrentVersion.targets(2106,5): warning MSB3277: Found conflicts between different versions of "System.Threading.ThreadPool" that could not be resolved.  These reference conflicts are listed in the build log when log verbosity is set to detailed.
3>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Current\Bin\Microsoft.Common.CurrentVersion.targets(2106,5): warning MSB3277: Found conflicts between different versions of "System.Threading.Timer" that could not be resolved.  These reference conflicts are listed in the build log when log verbosity is set to detailed.
3>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Current\Bin\Microsoft.Common.CurrentVersion.targets(2106,5): warning MSB3277: Found conflicts between different versions of "System.Memory" that could not be resolved.  These reference conflicts are listed in the build log when log verbosity is set to detailed.

Answer 1

这里的问题是至少针对“System.Collections.Concurrent”的强命名和混合程序集版本，但可能针对所有 28 个警告。

我尝试在解决方案级别进入 NuGet 以安装缺少的程序集，但选择列表中甚至没有 4.0.14。

您看到的版本是 NuGet 版本，与程序集版本不同。例如NuGet 版本 4.3.0-preview1-24530-04 具有适用于 .NET 标准 1.3 的程序集版本 4.0.13.0：

请注意，在同一个包中，netcore50 的汇编版本是 4.0.10.0！

这是微软的错误吗？

不，这是一项功能。当程序集为 strong named. 时，完整版本应匹配。如果没有，这将给出警告。不使用 GAC 时，只能发布程序集的一个版本 - 如果使用多个版本，则使用哪个版本？注意——所有微软的程序集都是强命名的。

这里的问题：

• 您正在包含一个（强命名）程序集，该程序集构建到 System.Collections.Concurrent 程序集版本 4.0.14.0
• 您正在（间接）在应用程序程序集版本 4.0.11.0 中使用 System.Collections.Concurrent 程序集。

所以一个程序集有两个版本！

解决方案

有多种可能的解决方案：

1. 对 System.Collections.Concurrent 使用相同的程序集版本（您需要找出哪个 NuGet 包是程序集版本 4.0.14.0）。这在大多数情况下是不可行的。
2. 将版本 4.0.11.0 和 4.0.14.0 安装到 GAC 中 - 这几天也不是一个非常流行的选项 -> .NET Core 不可能，因为 .NET Core 没有 GAC。见Is there any GAC equivalent for .NET Core?

3. 在您的 .config 中使用 <bindingRedirect>。见Redirecting Assembly Versions | Microsoft Docs

   例如对于“System.Collections.Concurrent”：

   <dependentAssembly>
       <assemblyIdentity name="System.Collections.Concurrent" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />
       <bindingRedirect oldVersion="4.0.0.0-4.0.14.0" newVersion="4.0.11.0" />
   </dependentAssembly>
   

结语

有 28 个版本问题，但有一个很大的变化是通过单个 bindingRedirect 解决了多个问题。所以最好的方法是从一个（最好是最顶层的）开始，然后重新构建并重复，直到所有问题都解决。

还请注意，降级程序集有点棘手，例如，基于 4.0.13.0 构建的程序集可以使用 4.0.11.0+ 中引入/更改的功能。因此，您还可以更新您的版本并在“newVersion”属性中使用该版本

Answer 2

为每个程序集绑定重定向 (bindingRedirect)，您可以在配置中手动执行此操作，或者在项目文件属性中有一个选项。 检查它然后升级。