C# 用C语言中的列组合过滤唯一数据#

我的清单如下：

 public class MyClass
 {
    public int val1;
    public long val2;
    public string val3;
 }
class Program
{
    static void Main(string[] args)
    {
        List<MyClass> lstData=new List<MyClass>
        {
            new MyClass{val1=1,val2=2,val3="AA"},
            new MyClass{val1=1,val2=2,val3="BB"},
            new MyClass{val1=3,val2=4,val3="AA"},
            new MyClass{val1=3,val2=4,val3="BB"},
            new MyClass{val1=1,val2=2,val3="BB"},
            new MyClass{val1=3,val2=4,val3="AA"},

        };
    }
}

我想消除重复的行，并从列表中删除不同的行。

---

我如何做到这一点？

假设您的真实类

MyClass

覆盖

等于
和
GetHashCode
，您只需添加：

var result = lstData.GroupBy(x=>new {x.val1, x.val2, x.val3}, (x,y)=>y.First())
                    .ToList();                        

您必须在
MyClass
类上实现
GetHashCode
和
Equals
方法，或者定义实现
IEqualityComparer
的自定义类

var result = lstData.GroupBy(x=>new {x.val1, x.val2, x.val3}, (x,y)=>y.First())
                    .ToList();                        

lstData = lstData.Distinct().ToList();

public class MyClassEqualityComparer : IEqualityComparer<MyClass>
{
    private static Lazy<MyClassEqualityComparer> _instance = new Lazy<MyClassEqualityComparer>(() => new MyClassEqualityComparer());

    public static MyClassEqualityComparer Instance
    {
        get { return _instance.Value; }
    }

    private MyClassEqualityComparer() { }

    public bool Equals(MyClass x, MyClass y)
    {
        return x.val1 == y.val1 && x.val2 == y.val2 && x.val3 == y.val3;
    }

    public int GetHashCode(MyClass obj)
    {
        return obj.val1.GetHashCode() ^ obj.val2.GetHashCode() ^ obj.val3.GetHashCode();
    }
}

var distinct = lstData.Distinct(MyClassEqualityComparer.Instance).ToList();