C# list＜T＞去重

文章目录

[C# list<T>去重](# list去重)
- 值类型去重
- - List<object>
  - - [object is int](#object is int)
    - [object is decimal](#object is decimal)
    - [object is char](#object is char)
    - [object is bool](#object is bool)
    - [object is string](#object is string)
  - List<int>
  - List<string>
- 引用类型去重

C# list去重

值类型去重

List

object is int

csharp 复制代码

//object is int
   List<object> ointList = new List<object>();
   ointList.Add(1);
   ointList.Add(1);
   ointList.Add(2);
   ointList = ointList.Distinct().ToList();

object is decimal

csharp 复制代码

//object is decimal
            List<object> odecimalList = new List<object>();
            odecimalList.Add(1.25);
            odecimalList.Add(1.25);
            odecimalList.Add(2.25);
            odecimalList = odecimalList.Distinct().ToList();

object is char

csharp 复制代码

            //object is char
            List<object> ocharList = new List<object>();
            ocharList.Add('a');
            ocharList.Add('a');
            ocharList.Add('b');
            ocharList = ocharList.Distinct().ToList();

object is bool

csharp 复制代码

            //object is bool
            List<object> oboolList = new List<object>();
            oboolList.Add(true);
            oboolList.Add(false);
            oboolList.Add(true);
            oboolList = oboolList.Distinct().ToList();

object is string

csharp 复制代码

            //object is string
            List<object> osList = new List<object>();
            osList.Add("1");
            osList.Add("1");
            osList.Add("2");
            osList = osList.Distinct().ToList();

List

csharp 复制代码

            List<int> intList = new List<int>();
            intList.Add(1111);
            intList.Add(1111);
            intList.Add(2222);
            intList = intList.Distinct().ToList();

List

csharp 复制代码

            List<string> idList = new List<string>();
            idList.Add("1111");
            idList.Add("1111");
            idList.Add("2222");  
            idList = idList.Distinct().ToList();

引用类型去重

csharp 复制代码

private class NetworkCtrl
        {

            #region <属性>

            /// <summary>
            /// 网控对象ID
            /// </summary>
            public string NetCtrlId { get; set; }

            /// <summary>
            /// 业务对象ID
            /// </summary>
            public string InterID { get; set; }

            /// <summary>
            /// 业务操作
            /// </summary>
            public string OperationDesc { get; set; }
            #endregion <属性>

        }

csharp 复制代码

List<NetworkCtrl> ncList = new List<NetworkCtrl>();
            ncList.Add(new NetworkCtrl
            {
                InterID = "100148",
                NetCtrlId = "9cc2c432-56a9-b38d-11ee-794e3a9853e2",
                OperationDesc = "售后单-SH231103001-下推其它出库单"
            });
            ncList.Add(new NetworkCtrl
            {
                InterID = "100149",
                NetCtrlId = "9cc2c432-56a9-b38d-11ee-794e3a9853e2",
                OperationDesc = "售后单-SH231103002-下推其它出库单"
            });
            ncList.Add(new NetworkCtrl
            {
                InterID = "100148",
                NetCtrlId = "9cc2c432-56a9-b38d-11ee-794e3a9853e2",
                OperationDesc = "售后单-SH231103001-下推其它出库单"
            });
            var ncList1 = ncList.Distinct().ToList();
            var ncList2 = ncList.GroupBy(x => x.InterID).Select(y => y.First()).ToList();

集合里有三条记录，其中两条重复。

使用Distinct后，还有三条，说明distinct失败

原因是，引用类型即使属性一样，引用地址是不一样的。

只能用别的方式去避免。