System.TypeLoadException未处理:无法加载类型,因为该方法没有实现(没有RVA)

时间:2013-06-01 22:41:44

标签: c# reflection

我正在尝试通过输入字符串来执行命令。我有以下课程:

abstract class ECommand {
    public static bool TryExecute(string raw, out object result) {
        string name = raw; //function trigger
        if (!Config.CommandRegister.ContainsKey(name)) {
            result = null;
            return false;
        }

        Type datType = Config.CommandRegister[name];
        var instance = Activator.CreateInstance(datType);
        MethodInfo method = datType.GetMethod("Execute");
        result = method.Invoke(instance, null);

        return true;
    }

    public extern object Execute();
}

字符串和等效类型在这样的字典中注册:

public static Dictionary<string, Type> CommandRegister = 
new Dictionary<string, Type> { {"test", typeof(TestECommand)} };     

我尝试在这个课上测试它:

class TestECommand : ECommand {
    public new object Execute() {
        Console.WriteLine("test");
        return "k";
    }
}

调用时

ECommand.TryExecute(source, out res);

我得到以下例外:

System.TypeLoadException was unhandled
  HResult=-2146233054
  Message=Could not load type 'Test.ECommand' from assembly 'Test, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' because the method 'Execute' has no implementation (no RVA).
  Source=Test
  TypeName=Test.ECommand

我做错了什么?

1 个答案:

答案 0 :(得分:1)

我认为你混淆了extern关键字 - 它通常用于P / invoke。

我认为你的意思是abstract

public abstract object Execute();