LINQ to Objects(1)

对于一个集合,只要该集合实现了System.Collections.IEnumerable接口,或者是泛型接口:System.Collections,Generic.IEnumerable<T>,就可以使用LINQ查询该集合数据.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace LinqObject
{
    class Program
    {
        static void Main(string[] args)
        {
            Int32[] myNnums = new int[] { 1, 4, 9, 16, 22, 25, 56, 79 };
            //System.Linq.Enumerable.WhereArrayIterator<int> everyNums = from p in myNnums
            var everyNums = from p in myNnums
                            where (p % 2) == 0
                            select p;
            Console.WriteLine("结果:");
            foreach (int val in everyNums) {
                Console.WriteLine(val.ToString());
            }
        }
    }
}

二:查询对象列表

1,建model:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace LinqObject.models
{
    public class PlayerInfoVO
    {
        private string name;
        public string Name
        {
            get { return name; }
            set { name = value; }
        }
        private uint id;
        public uint Id
        {
            get { return id; }
            set { id = value; }
        }
        private uint level;
        public uint Level
        {
            get { return level; }
            set { level = value; }
        }
    }
}

2,建IEnumerable<PlayerInfoVO>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using LinqObject.listmodel;
namespace LinqObject.listmodel
{
    public class PlayerList
    {
        private static PlayerList myInstance;
        public static PlayerList Instance() {
            if (myInstance == null) myInstance = new PlayerList();
            return myInstance;
        }
        public PlayerList() {
            if (myInstance != null)
            {
                throw new Exception("PlayerList 被设计成 单例!!!");
            }
            else {
                myInstance = this;
            }
        }
        public IEnumerable<models.PlayerInfoVO> CreatePlayerInfoVo() {
            return new List<models.PlayerInfoVO>
            {
                new models.PlayerInfoVO{ Id=1, Name = "Ainy" , Level = "1"},
                new models.PlayerInfoVO{ Id=2, Name = "Aonaufly" , Level = "2"}
            };
        }
    }
}
改写

Main

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using LinqObject.listmodel;
using LinqObject.models;
namespace LinqObject
{
    class Program
    {
        static void Main(string[] args)
        {
            Int32[] myNnums = new int[] { 1, 4, 9, 16, 22, 25, 56, 79 };
            //System.Linq.Enumerable.WhereArrayIterator<int> everyNums = from p in myNnums
            var everyNums = from p in myNnums
                            where (p % 2) == 0
                            select p;
            Console.WriteLine("结果:");
            foreach (int val in everyNums) {
                Console.WriteLine(val.ToString());
            }
            var result = from c in PlayerList.Instance().CreatePlayerInfoVo()
                         where c.Name == "Aonaufly"
                         select c;
            Console.WriteLine(result);
        }
    }
}