如何从.NET Framework调用.NET Core程序集中的方法

Question

我有两个组件：

1. 父程序集是针对.NET Framework编译的。
2. 子程序集是针对.NET Core编译的。

我想在子程序集中调用一个方法，并检索它的返回对象。构造函数不接受任何参数。该方法不接受任何参数，并返回Microsoft.OData.Edm.IEdmModel

到目前为止我尝试过的事情：

1. 创建一个单独的appdomain，并调用domain.CreateInstanceAndUnwrap：

AppDomainSetup setup = new AppDomainSetup()
{
   ApplicationBase = path
   PrivateBinPath = path
};
AppDomain domain = AppDomain.CreateDomain("Child", null, setup);
AssemblyName assemblyName = AssemblyName.GetAssemblyName(assemblyPath);
object instance = domain.CreateInstanceAndUnwrap(assemblyName.FullName, className);

2. 创建一个扩展MarshalByRefObject的类，并使用它来加载程序集，调用该函数，并编组返回类型：

AppDomain domain = AppDomain.CreateDomain("Child");
BinaryMarshal marshal = (BinaryMarshal) domain.CreateInstanceAndUnwrap(typeof(BinaryMarshal).Assembly.FullName, typeof(BinaryMarshal).FullName);
IEdmModel model = marshal.LoadEdmModel(path, className, functionName);

//BinaryMarshal.cs:
internal class BinaryMarshal : MarshalByRefObject
{
    public IEdmModel LoadEdmModel(string binary, string className, string functionName)
    {
        Assembly assembly = Assembly.LoadFrom(binary);
        Type type = assembly.GetType(className);  //returns null because of exception listed below
     }
}

在这两种情况下，代码都不起作用，因为以下异常（从Fuslogvw.exe获得）：

*** Assembly Binder Log Entry  (4/29/2019 @ 10:34:48 AM) ***

The operation failed.
Bind result: hr = 0x80070002. The system cannot find the file specified.

Assembly manager loaded from:  C:\Windows\Microsoft.NET\Framework64\v4.0.30319\clr.dll
Running under executable  C:\develop\parent\out\debug-amd64\Parent.exe
--- A detailed error log follows. 

=== Pre-bind state information ===
LOG: DisplayName = System.Runtime, Version=4.2.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
 (Fully-specified)
LOG: Appbase = file:///C:/develop/parent/out/debug-amd64/
LOG: Initial PrivatePath = NULL
LOG: Dynamic Base = NULL
LOG: Cache Base = NULL
LOG: AppName = Parent.exe
Calling assembly : Child, Version=5.0.0.0, Culture=neutral, PublicKeyToken=null.
===
LOG: This bind starts in LoadFrom load context.
WRN: Native image will not be probed in LoadFrom context. Native image will only be probed in default load context, like with Assembly.Load().
LOG: Using application configuration file: C:\develop\parent\out\debug-amd64\Parent.exe.Config
LOG: Using host configuration file: 
LOG: Using machine configuration file from C:\Windows\Microsoft.NET\Framework64\v4.0.30319\config\machine.config.
LOG: Post-policy reference: System.Runtime, Version=4.2.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
LOG: GAC Lookup was unsuccessful.
LOG: Attempting download of new URL file:///C:/develop/parent/out/debug-amd64//System.Runtime.DLL.
LOG: Attempting download of new URL file:///C:/develop/parent/out/debug-amd64//System.Runtime/System.Runtime.DLL.
LOG: Attempting download of new URL file:///C:/develop/parent/out/debug-amd64//System.Runtime.EXE.
LOG: Attempting download of new URL file:///C:/develop/parent/out/debug-amd64//System.Runtime/System.Runtime.EXE.
LOG: Attempting download of new URL file:///C:/develop/child/out/debug-amd64/netcoreapp2.0/System.Runtime.DLL.
LOG: Attempting download of new URL file:///C:/develop/child/out/debug-amd64/netcoreapp2.0/System.Runtime/System.Runtime.DLL.
LOG: Attempting download of new URL file:///C:/develop/child/out/debug-amd64/netcoreapp2.0/System.Runtime.EXE.
LOG: Attempting download of new URL file:///C:/develop/child/out/debug-amd64/netcoreapp2.0/System.Runtime/System.Runtime.EXE.
LOG: All probing URLs attempted and failed.

据我所知，它正在尝试加载System.Runtime，因为父app已经加载了不同版本的System.Runtime，因此失败了。

这甚至可能吗？

Answer 1

.NET Core和.NET Framework是不同的运行时。尝试将.NET Standard用于公共库，您将能够从.NET Core和.NET Framework中使用它。

Answer 2

答案很简单：您不能直接从.NET Framework调用.NET Core程序集，反之亦然。 .NET Core与.NET Framework不兼容。

您可以从.NET Framework程序集中调用.NET Core的兼容程序集，只要该程序集的目标是使用.NET Standard，最好至少使用.NET Standard 2.0来提供与.NET Core 2.1和2.2运行时的兼容性。

另请参阅.NET标准的官方文档：https://docs.microsoft.com/en-us/dotnet/standard/net-standard