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删除列表中的重复对象 (C#)

更新时间:2023-02-13 22:22:31

您需要使用 Distinct 的第二个重载,它采用 IEqualityComparer 实例作为第二个参数.像这样定义一个比较器:

You need to use the second overload of Distinct that takes an IEqualityComparer<TimeMetric> instance as a second parameter. Define a comparer like this:

class MyComparer : IEqualityComparer<TimeMetric>
{
    public bool Equals(TimeMetric x, TimeMetric y)
    {
        return x.MetricText.Equals(y.MetricText);
    }

    public int GetHashCode(TimeMetric obj)
    {
        return obj.MetricText.GetHashCode();
    }
}

重要提示:上面的代码没有检查 MetricText 属性为 null 的情况(听起来可能是, 因为它很可能是一个 string).如果 MetricTextnull,您应该这样做并从 GetHashCode 返回 0.另一方面,如果MetricText的类型是值类型,则不需要进行任何修改.

Important note: The above code does not check for the case where the MetricText property is null (and it sounds like it could be, since it's most probably a string). You should do that and return 0 from GetHashCode if MetricText is null. On the other hand, if the type of MetricText is a value type, you don't need to perform any modification.

然后:

var list = new List<TimeMetric> { ... };
var unique = list.Distinct(new MyComparer());