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比较泛型接口类型与给定类型

types reflection c#

Tomtom · 技术社区 · 8 年前

我试图动态地创建一个从泛型继承的类型的实例 interface

例如,我有以下基本接口,其中派生了几个其他接口:

public interface IDummy { }

我有两个派生接口:

public interface IDummyDerived<T> : IDummy
{
  void Foo(T value);
}

public interface ITempDerived<T> : IDummy
{
  void HelloWorld(T value);
}

现在我需要一个ServiceProvider类,在这里我可以创建并找到实现给定接口的类。每个接口(idummydrived和ITempDerived)只实现一次。

internal class DummyServiceProvider
{
  public T GetDummy<T>() where T : IDummy
  {
    Type baseType = typeof(IDummy);
    Type[] types = AppDomain.CurrentDomain.GetAssemblies().SelectMany(a => a.GetTypes()).Where(p => baseType.IsAssignableFrom(p) && p.IsClass).ToArray();
    //now I have all classes which implements one of my interfaces
    foreach(Type type in types)
    {
      // here I want to check if the current type is typeof(T)
      // (typeof(T) == type) ->  doesn't work
      // (type.GetGenericTypeDefinition() == type) doesnt work

    }
  }
  return default(T);
}

如何正确比较给定的 typeof(T) 到类型数组中的类型?

--更新:

DummyServiceProvider的用法如下所示:

IDummyDerived<string> dummyDerived = myDummyServiceProvider.GetDummy<IDummyDerived<string>>()

3 回复 | 直到 8 年前

Andre 8 年前

一个更简单的解决方案是重写你的where,如下所示

string nameOfIDummy = typeof(IDummy).Name;
string nameOfT = typeof(T).Name;
IEnumerable<Type> classTypes = AppDomain.CurrentDomain.GetAssemblies().SelectMany(a => a.GetTypes()).Where(p => p.IsClass && p.GetInterface(nameOfIDummy) != null && p.GetInterface(nameOfT ) != null);

Community Mohan Dere 6 年前

你在检查 base generic interface type 具有 derived type

参见下面的代码

using System;
using System.Reflection;
using System.Linq;

namespace AssemblyLoadRefelectionExp
{
    public class MyClass
    {
        public string Key { get; set; }
    }

    public interface IDummy { }

    public interface IDummyDerived<T> : IDummy
    {
        void Foo(T value);
    }

    public interface ITempDerived<T> : IDummy
    {
        void HelloWorld(T value);
    }

    public class DummyDerived<T> : IDummyDerived<T>
    {
        public void Foo(T value)
        {
            Console.WriteLine("DummyDerived`1 ->Foo");
        }
    }

    public class AnotherDummy : IDummyDerived<string>
    {
        public void Foo(string value)
        {
            Console.WriteLine("AnotherDummy -> Foo");
        }
    }

    public class Program
    {
        public static void Main()
        {
            Console.WriteLine($"Is {typeof(DummyDerived<MyClass>)} equal to {typeof(IDummyDerived<MyClass>)} : {CheckType<DummyDerived<MyClass>>(typeof(IDummyDerived<MyClass>))}");
            Console.WriteLine("---------------------------------");
            GetDummy<IDummyDerived<string>>();

            Console.ReadLine();
        }

        public static bool CheckType<T>(Type type)
        {
            return typeof(T) == type ? true : false;
        }

        public static T GetDummy<T>() where T : IDummy
        {
            Type baseType = typeof(IDummy);
            Type[] types = AppDomain.CurrentDomain.GetAssemblies().SelectMany(a => a.GetTypes()).Where(p => baseType.IsAssignableFrom(p) && p.IsClass).ToArray();
            //now I have all classes which implements one of my interfaces
            foreach (Type type in types)
            {
                Console.WriteLine($"Is {type.Name} assignable from {typeof(T)} : {typeof(T).IsAssignableFrom(type)}");
            }

            return default(T);
        }
    }
}

输出为

正在组装lyLoadRefelectionExp.dummy导出 1[AssemblyLoadRefelectionExp.MyClass] equal to AssemblyLoadRefelectionExp.IDummyDerived 1[装配lyLoadRefelectionExp.MyClass类]:错误`

Dummy是派生的吗 1 assignable from AssemblyLoadRefelectionExp.IDummyDerived 1[系统字符串]:错误

是否可以从Assemb分配另一个虚拟对象lyLoadRefelectionExp.idummydrived文件`1[系统字符串]:正确

IsAssignableFrom 方法自 GetDummy 方法正在用调用 IsAssignableFrom公司