c# - 区分用于引用对象的类型及其后备存储的类型

Question

using System;

interface IAnimal
{
}

class Cat: IAnimal
{
}

class Program
{
    public static void Main(string[] args)
    {
        IAnimal cat = new Cat();

        // Console.WriteLine(cat.GetType());
           // This would only give me the type of 
           // the backing store, i.e. Cat. Is there a 
           // way I can get to know that the identifier 
           // cat was declared as IAnimal?

        Console.ReadKey();
    }
}

更新:感谢 Dan Bryant 的提醒。

using System;
using System.Reflection;
using System.Collections.Generic;
using System.Linq;

namespace TypeInfo
{
    class Program
    {
        public static void Main(string[] args)
        {
            IAnimal myCat = new Cat();
            ReflectOnType();
            Console.ReadKey();
        }

        public static void ReflectOnType()
        {
            Assembly.GetExecutingAssembly().
                GetType("TypeInfo.Program").
                GetMethod("Main", 
                BindingFlags.Static| BindingFlags.Public).
                GetMethodBody().LocalVariables.
                ToList().
                ForEach( l => Console.WriteLine(l.LocalType));
        }
    }

    interface IAnimal { }
    class Cat : IAnimal { }
}

Answer 1

您可以使用泛型类型推断:

using System;

internal interface IAnimal
{
}

internal class Cat : IAnimal
{
}

class Program
{
    static void Main()
    {
        var cat = new Cat();
        Console.WriteLine(cat.GetType()); // Cat
        Console.WriteLine(GetStaticType(cat)); // Cat

        IAnimal animal = cat;
        Console.WriteLine(GetStaticType(animal)); // IAnimal
    }

    static Type GetStaticType<T>(T _)
    {
        return typeof (T);
    }
}