C# Issues and Solutions -- Method get_XXX from assembly YYYY does not have an implementation_assembly.gettypes() '' does not have an implementa-优快云博客

本文通过一个具体的示例详细解释了TypeLoadException的发生原因及其复现步骤。通过创建接口定义与实现类库项目，并在客户端项目中引用这两种类库，演示了当实现类库针对不同版本的接口重新编译时如何引发TypeLoadException异常。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

This can occur if you have an interface in one assembly and its implementation in another, and the implementation assembly was built against a different version of the interface.

If you want to try reproducing this, try the following:
   1. Create a class library project: InterfaceDef, add just one class, and build:
public interface IInterface { string GetString(string key); //short GetShort(string key); }
   2. Create a second class library project: Implementation (with separate solution), copy InterfaceDef.dll into project directory and add as file reference, add just one class, and build:

public class ImplementingClass : IInterface { #region IInterface Members public string GetString(string key) { return "hello world"; } //public short GetShort(string key) //{ // return 1; //} #endregion }
3. Create a third, console project: ClientCode, copy the two dlls into the project directory, add file references, and add the following code into the Main method:

IInterface test = new ImplementingClass(); string s = test.GetString("dummykey"); Console.WriteLine(s); Console.ReadKey();
4. Run the code once, the console says "hello world"
5. Uncomment the code in the two dll projects and rebuild - copy the two dlls back into the ClientCode project, rebuild and try running again. TypeLoadException occurs when trying to instantiate the ImplementingClass.

http://stackoverflow.com/questions/948785/typeloadexception-says-no-implementation-but-it-is-implemented