C# - 无法覆盖==

Question

我有以下类(为Unity游戏引擎构建)

using System;
using System.Collections.Generic;
using UnityEngine;

public class Biome : ScriptableObject, IEquatable<Biome>
{
    // ...

    //
    // IEquatable
    //

    public bool Equals(Biome other)
    {
        if (other == null)
            return false;

        return this.name == other.name;
    }

    public override bool Equals(object obj)
    {
        if (obj == null) return false;

        Biome other = obj as Biome;

        if (other == null) return false;

        return Equals(other);
    }

    public override int GetHashCode()
    {
        return this.name.GetHashCode();
    }

    public static bool operator ==(Biome biome1, Biome biome2)
    {
        if (object.ReferenceEquals(biome1, biome2)) return true;
        if (object.ReferenceEquals(null, biome1)) return false;
        if (object.ReferenceEquals(null, biome2)) return false;

        return biome1.Equals(biome2);
    }

    public static bool operator !=(Biome biome1, Biome biome2)
    {
        if (object.ReferenceEquals(biome1, biome2)) return false;
        if (object.ReferenceEquals(biome1, null)) return true;
        if (object.ReferenceEquals(biome2, null)) return true;

        return !biome1.Equals(biome2);
    }
}

当我尝试进行测试时,该功能Equals似乎正在工作,但操作员==给了我不同的结果.

    [Test]
    public void FooTest()
    {
        ScriptableObject biome1 = ScriptableObject.CreateInstance("Biome");
        ScriptableObject biome2 = ScriptableObject.CreateInstance("Biome");

        biome1.name = "Biome #1";
        biome2.name = "Biome #1";

        Assert.IsTrue(biome1.Equals(biome2));
        Assert.IsTrue(biome1 == biome2);  // This one fails

    }

我的实施有问题吗？

更新:这是完整的课程,如果它有所作为:https://www.hastebin.com/divazubero.cpp

Answer 1

问题是你的变量属于类型ScriptableObject,而不是类型Biome.

编译器必须在编译时决定调用哪个重载.并且由于它在编译时不知道运行时类型Biome,它会触发对==运算符的调用ScriptableObject.
如果该类没有重写的==运算符,object则调用运算符(ReferenceEquals当然这很简单false).

==运算符重载不是 virtual.

如果您在测试中使用特定 类型Biome,它将按预期工作.