统一列表(C#)

Question

我正在尝试使用自定义相等比较器从列表中删除重复项,但我似乎无法做到正确.

简化示例:

class A
{
    public A(string Test) { this.Test = Test; }
    public string Test;
    public string ToString() { return Test; }
}

class AsComparer: EqualityComparer<A>
{
    public override bool Equals(A x, A y)
    {
        return (x.Test == y.Test);
    }

    public override int GetHashCode(A obj)
    {
        return obj.Test.GetHashCode();
    }
}

static private void Test()
{
    var As = new List<A> { new A("Test1"), new A("Test3"), new A("Test1"), new A("Test2") };
    As.Distinct(new AsComparer());
    As.Sort((e1, e2) => { return (e1.Test.CompareTo(e2.Test)); });
}

这将返回集合"Test1","Test1","Test2","Test3".我希望只有一个"Test1",但似乎无法弄清楚如何做到这一点.

有任何想法吗？

Answer 1

Distinct返回一个IEnumerable<T>,它不在源列表本身上运行.你必须这样做:

As = As.Distinct(new AsComparer()).ToList()

您还可以在此处包括您的排序:

As = As
    .Distinct(new AsComparer())
    .OrderBy(x => x.Test)
    .ToList()

Answer 2

Distinct()返回一个全新的IEnumerable,所以:

var result = 
  As.
    Distinct(new AsComparer()).
    OrderBy(e => e.Test).
    ToList();