Equals()和==是否相同取决于实现。因为c#允许用户分别为Equals()和==设置不同的行为。

    class CompareTest
    {
        public readonly int val;

        public CompareTest(int val)
        {
            this.val = val;
        }

        public override bool Equals(object obj)
        {
            return obj is CompareTest test && this.val == test.val;
        }

        public override int GetHashCode()
        {
            return val;
        }

        public static bool operator == (CompareTest a, object b)
        {
            return Equals(a, b);
        }

        public static bool operator != (CompareTest a, object b)
        {
            return !(a == b);
        }
    }

在本例中，我使Equals()和==具有相同的行为。但如果我让他们不一样呢?例如:

        public static bool operator == (CompareTest a, object b)
        {
            return false;
        }

Equals()正常工作，但==永远不会工作。

此外，虽然我让它们具有相同的行为，但仍然有一个区别:哪个==函数将被调用取决于左边的值:

        Compare Test a = new CompareTest(1);
        object b = new CompareTest(1);
        CompareTest c = new CompareTest(1);
        Debug.Log("AB " + (a == b)); // true
        Debug.Log("BA " + (b == a)); // false! because it calls object's == function 
        Debug.Log("AC " + (a == c)); // true
        Debug.Log("CA " + (c == a)); // true

给答案再加一分。

. equalsto()方法提供了比较区域性和区分大小写的方法。

The == token in C# is used for two different equality-check operators. When the compiler encounters that token, it will check whether either of the types being compared has implemented an equality-operator overload for either the specific combination types being compared(*), or for a combination of types to which both types can be converted. If the compiler finds such an overload it will use it. Otherwise, if the two types are both reference types and they are not unrelated classes (either may be an interface, or they may be related classes), the compiler will regard == as a reference-comparison operator. If neither condition applies, compilation will fail.

请注意，其他一些语言为两个相等检查操作符使用单独的令牌。在VB。例如，=令牌在表达式中仅用于可重载的相等检查操作符，而is则用作引用测试或空测试操作符。在没有覆盖相等检查操作符的类型上使用=将会失败，在测试引用是否相等或为空之外的任何目的上尝试使用Is也会失败。

(*)Types generally only overload equality for comparison with themselves, but it may be useful for types to overload the equality operator for comparison with other particular types; for example, int could have (and IMHO should have but didn't) defined an equality operators for comparison with float, so that 16777217 would not report itself equal to 16777216f. As it is, since no such operator is defined, C# will promote the int to float, rounding it to 16777216f before the equality-check operator sees it; that operator then sees two equal floating-point numbers and reports them as equal, unaware of the rounding that took place.

据我所知，答案很简单:

==比较对象引用。 . equals比较对象内容。 字符串数据类型的作用总是类似于内容比较。

我希望我是对的，这回答了你的问题。

Equals()和==是否相同取决于实现。因为c#允许用户分别为Equals()和==设置不同的行为。

    class CompareTest
    {
        public readonly int val;

        public CompareTest(int val)
        {
            this.val = val;
        }

        public override bool Equals(object obj)
        {
            return obj is CompareTest test && this.val == test.val;
        }

        public override int GetHashCode()
        {
            return val;
        }

        public static bool operator == (CompareTest a, object b)
        {
            return Equals(a, b);
        }

        public static bool operator != (CompareTest a, object b)
        {
            return !(a == b);
        }
    }

在本例中，我使Equals()和==具有相同的行为。但如果我让他们不一样呢?例如:

        public static bool operator == (CompareTest a, object b)
        {
            return false;
        }

Equals()正常工作，但==永远不会工作。

此外，虽然我让它们具有相同的行为，但仍然有一个区别:哪个==函数将被调用取决于左边的值:

        Compare Test a = new CompareTest(1);
        object b = new CompareTest(1);
        CompareTest c = new CompareTest(1);
        Debug.Log("AB " + (a == b)); // true
        Debug.Log("BA " + (b == a)); // false! because it calls object's == function 
        Debug.Log("AC " + (a == c)); // true
        Debug.Log("CA " + (c == a)); // true

==和. equals都依赖于实际类型中定义的行为和调用位置上的实际类型。两者都只是方法/操作符，可以在任何类型上重写，并给定作者希望的任何行为。根据我的经验，我发现人们在对象上实现. equals却忽略了operator ==是很常见的。这意味着. equals将实际测量值是否相等，而==将测量它们是否是相同的引用。

当我处理一个定义不断变化的新类型或编写泛型算法时，我发现最佳实践如下

如果我想在c#中比较引用，我使用Object。直接使用ReferenceEquals(在泛型情况下不需要) 如果我想比较值，我使用EqualityComparer<T>。默认的

在某些情况下，当我觉得==的用法不明确时，我会显式地使用Object。在代码中引用等号以消除歧义。

Eric Lippert最近写了一篇博文，主题是为什么在CLR中有两种相等的方法。值得一读

http://blogs.msdn.com/ericlippert/archive/2009/04/09/double-your-dispatch-double-your-fun.aspx