For C# projects, the target of x86 does what it sounds like. It says that this assembly only supports x86 architectures. Likewise for x64. Any CPU on the other hand says that I don't care which architecture, I support both. So, the next 2 questions are (1) what is the configuration of the executable that uses these dlls? and (2) what is the bitness of your OS/Computer? The reason I ask is because if your executable is compiled to run in 64-bit, then it NEEDS all dependencies to be able to run in 64-bit mode as well. Your Any CPU assembly should be able to be loaded, but perhaps it is referencing some other dependency that is only capable of running in x86 configuration. Check all dependencies and dependencies-of-dependencies to make sure everything is either "Any CPU" or "x64" if you plan to run the executable in 64-bit mode. Otherwise, you'll have issues.

在许多方面，Visual Studio并没有使编译任意CPU和各种依赖于体系结构的程序集的混合变得容易。这是可行的，但它通常要求必须针对x86和x64分别编译“任何CPU”的程序集，因为某个依赖的某个依赖有两个版本。

There should be a way to make a .NET EXE/DLL AnyCPU, and any unmanaged DLLs it depends on compiled both with x86 and x64, both bundled perhaps with different filenames and then the .NET module dynamically loading the correct one based on its runtime processor architecture. That would make AnyCPU powerful. If the C++ DLL only supports x86 or x64 then AnyCPU is of course pointless. But the bundling both idea I have yet to see implemented as the configuration manager does not even provide a means to build the same project twice with a different configuration/platform for multiple bundling allowing AnyCPU or even other concepts like any configuration to be possible.

对于我的项目，我要求能够构建到x86和x64。这样做的问题是，每当您在使用一个引用时添加引用，那么当您构建另一个引用时它就会报错。

我的解决方案是手动编辑*。Csproj文件，这样行:

<Reference Include="MyLibrary.MyNamespace, Version=1.0.0.0, Culture=neutral, processorArchitecture=x86"/>

<Reference Include="MyLibrary.MyNamespace, Version=1.0.0.0, Culture=neutral, processorArchitecture=AMD64"/>

<Reference Include="MyLibrary.MyNamespace, Version=1.0.0.0, Culture=neutral, processorArchitecture=MSIL"/>

改成这样:

<Reference Include="MyLibrary.MyNamespace, Version=1.0.0.0, Culture=neutral"/>

使用https://learn.microsoft.com/en-us/visualstudio/msbuild/customize-your-build # directorybuildprops-example:

在解决方案文件夹中添加一个Directory.Build.props文件 把这个粘贴进去:

<Project>
 <PropertyGroup>
   <ResolveAssemblyWarnOrErrorOnTargetArchitectureMismatch>None</ResolveAssemblyWarnOrErrorOnTargetArchitectureMismatch>
 </PropertyGroup>
</Project>

我以前遇到过类似的问题，特别是在向现有的x64解决方案(如SharePoint)添加测试解决方案时。在我的例子中，这似乎与默认情况下某些项目模板被添加为某些平台有关。

Here's the solution that often works for me: set everything to the correct platform in the Configuration Manager (the active configuration drop-down, says Debug normally, is a good way to get to it) and project platform (in project properties), then build, then set everything back to AnyCPU. Sometimes I have to remove and re-add some dependencies (DLLs in each project's Properties) and sometimes the "Run tests in 32 bit or 64 bit process" (double-click Local.testsettings and go to Hosts) has to be changed.

在我看来，这只是设定了一些事情，然后又把它放回去，但在幕后可能有更多我没有看到的事情发生。不过在过去，这对我来说是相当稳定的。

我今天遇到了这个问题，只是在Visual Studio中查看建筑配置并没有帮助，因为它显示了没有建造的项目和引用项目的任何CPU。

然后我在参考项目的csproj中找到了这个:

<PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
<DebugType>pdbonly</DebugType>
<Optimize>true</Optimize>
<OutputPath>bin\Release\</OutputPath>
<DefineConstants>TRACE</DefineConstants>
<ErrorReport>prompt</ErrorReport>
<WarningLevel>4</WarningLevel>
<PlatformTarget>x64</PlatformTarget>

不知怎么的，这个PlatformTarget是在配置更改的过程中添加的，而IDE似乎没有看到它。

从引用的项目中删除这一行解决了我的问题。