用于 SequenceEqual 的 IEqualityComparer [英] IEqualityComparer for SequenceEqual

问题描述

在 C# 中，是否有一个 IEqualityComparer 使用 SequenceEqual 方法来确定相等性?

In C#, is there an IEqualityComparer<IEnumerable> that uses the SequenceEqual method to determine equality?

推荐答案

.NET Framework 中没有这样的比较器，但您可以创建一个:

There is no such comparer in .NET Framework, but you can create one:

public class IEnumerableComparer<T> : IEqualityComparer<IEnumerable<T>>
{
    public bool Equals(IEnumerable<T> x, IEnumerable<T> y)
    {
        return Object.ReferenceEquals(x, y) || (x != null && y != null && x.SequenceEqual(y));
    }

    public int GetHashCode(IEnumerable<T> obj)
    {
        // Will not throw an OverflowException
        unchecked
        {
            return obj.Where(e => e != null).Select(e => e.GetHashCode()).Aggregate(17, (a, b) => 23 * a + b);
        }
    }
}

在上面的代码中，我遍历了 GetHashCode 中集合的所有项目.我不知道这是否是最明智的解决方案，但这在内部 HashSetEqualityComparer.

In the above code, I iterate over all items of the collection in the GetHashCode. I don't know if it's the wisest solution but this what is done in the internal HashSetEqualityComparer.

这篇关于用于 SequenceEqual 的 IEqualityComparer的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！