C# list常用的幾個操作 改變list中某個元素的值 替換某一段數據

 

1、改變list中某個元素的值

    public class tb_SensorRecordModel
    {
        public int ID { get; set; }
        public decimal Value1 { get; set; }
    }

            List<tb_SensorRecordModel> list = new List<tb_SensorRecordModel>();
            list.Add(new tb_SensorRecordModel { ID = 1, Value1 = 1 });
            list.Add(new tb_SensorRecordModel { ID = 2, Value1 = 2 });
            list.Add(new tb_SensorRecordModel { ID = 3, Value1 = 3 });

            //改變list中某個元素值
            var model = list.Where(c => c.ID == 2).FirstOrDefault();
            model.Value1 = 2222;

            list.ForEach(c =>
            {
                //打印的數據表明 list中的那個元素 確實被改變了
                //知識：引用、地址
                Console.WriteLine($"{c.ID},{c.Value1}");
            });
            Console.Read();
            return;

 

 

2、替換某一段數據

            List<tb_SensorRecordModel> list1 = new List<tb_SensorRecordModel>();
            list1.Add(new tb_SensorRecordModel { ID = 1, Value1 = 1 });
            list1.Add(new tb_SensorRecordModel { ID = 2, Value1 = 2 });
            list1.Add(new tb_SensorRecordModel { ID = 3, Value1 = 3 });
            list1.Add(new tb_SensorRecordModel { ID = 4, Value1 = 4 });
            list1.Add(new tb_SensorRecordModel { ID = 5, Value1 = 5 });

            //構造新的一段數據
            List<tb_SensorRecordModel> list2 = new List<tb_SensorRecordModel>();
            list2.Add(new tb_SensorRecordModel { ID = 2, Value1 = 2222 });
            list2.Add(new tb_SensorRecordModel { ID = 3, Value1 = 3333 });

            //刪除 舊的 那段數據
            list1.RemoveRange(1, 2);

            //將新的 這段數據 插入到 指定位置
            list1.InsertRange(1, list2);

            list1.ForEach(c =>
            {
                Console.WriteLine($"{c.ID},{c.Value1}");
            });
            Console.Read();
            return;