C# 获取List对象操作-查询属性、字段值合并、分组.......

            List<Model> strList = new List<Model>()
            {
                new Model(){Id=1,Name = "张三"},
                new Model(){Id=11,Name = "张三1"},
                new Model(){Id=2,Name = "李四"},
                new Model(){Id=3,Name = "王五"},
                new Model(){Id=30,Name = "王五"},
                new Model(){Id=4,Name = "赵六"},
            };
            //查询List对象某个字段
            var names = strList.Select(t => t.Name).ToList();
            //字段值合并
            string mergeName = string.Join("|", names.ToArray());

//根据某个字段分组  
var types = strList.GroupBy(x => x.Name)
                      .Select(group => new Model
                      {
                          Name = group.Key,
                      }).ToList();

//List中实现类似SQL 查询 select in...

List<int> whereList = new List<int>() { 1, 3 };
List<Model> list = strList.Where(x => whereList.Contains(x.Id)).ToList();
 
foreach (var model in list)
{
    Console.WriteLine("Id:" + model.Id + "Name:" + model.Name);
}
Console.WriteLine("list count==" + list.Count);    

//更改list中某个字段
list.ForEach(o => o.Age = 33);
 
list.All(o => { o.Age = 22; return true; });

1 2	`//List中获取最大值` `int` `maxA = list.Max(x => x.A);//获取链表中对象属性A的最大值`

　数组、list转化

List<string> listS=new List<string>();
listS.Add("str");
listS.Add("hello");
string[] str=listS.ToArray();
 
string[] stauts = dict[0].SDValue.Split('|');
List<string> tempStatus = new List<string>(stauts);
where = where.And(o => tempStatus.Contains(o.STATUS));