Redis总结（二）C#中如何使用redis

　　上一篇讲述了安装redis《Redis总结（一）Redis安装》，同时也大致介绍了redis的优势和应用场景。本篇着重讲解.NET中如何使用redis和C#。

　　Redis官网提供了很多开源的C#客户端。例如，Nhiredis ，ServiceStack.Redis ，StackExchange.Redis等。其中ServiceStack.Redis应该算是比较流行的。它提供了一整套从Redis数据结构都强类型对象转换的机制并将对象json序列化。所以这里只介绍ServiceStack.Redis，它也是目前我们产品中所使用的客户端。

　　ServiceStack.Redis地址：https://github.com/ServiceStack/ServiceStack.Redis

　　1. 建立一个控制台应用程序，并引用以下ServiceStack.Redis相关的四个类库。或者通过Nuget进行安装Redis常用组件ServiceStack.Redis。 下载示例代码。

　　2. 创建一个Redis操作的公用类RedisCacheHelper，

using System;
using System.Collections.Generic;
using System.Configuration;
using System.Linq;
using System.Text;
using System.Web;
using ServiceStack.Common.Extensions;
using ServiceStack.Redis;
using ServiceStack.Logging;

namespace Weiz.Redis.RedisTest
{
    public class RedisCacheHelper
    {
        private static readonly PooledRedisClientManager pool = null;
        private static readonly string[] redisHosts = null;
        public static int RedisMaxReadPool = int.Parse(ConfigurationManager.AppSettings["redis_max_read_pool"]);
        public static int RedisMaxWritePool = int.Parse(ConfigurationManager.AppSettings["redis_max_write_pool"]);

        static RedisCacheHelper()
        {
            var redisHostStr = ConfigurationManager.AppSettings["redis_server_session"];

            if (!string.IsNullOrEmpty(redisHostStr))
            {
                redisHosts = redisHostStr.Split(',');

                if (redisHosts.Length > 0)
                {
                    pool = new PooledRedisClientManager(redisHosts, redisHosts,
                        new RedisClientManagerConfig()
                        {
                            MaxWritePoolSize = RedisMaxWritePool,
                            MaxReadPoolSize = RedisMaxReadPool,
                            AutoStart = true
                        });
                }
            }
        }
        public static void Add<T>(string key, T value, DateTime expiry)
        {
            if (value == null)
            {
                return;
            }

            if (expiry <= DateTime.Now)
            {
                Remove(key);

                return;
            }

            try
            {
                if (pool != null)
                {
                    using (var r = pool.GetClient())
                    {
                        if (r != null)
                        {
                            r.SendTimeout = 1000;
                            r.Set(key, value, expiry - DateTime.Now);
                        }
                    }
                }
            }
            catch (Exception ex)
            {
                string msg = string.Format("{0}:{1}发生异常!{2}", "cache", "存储", key);
            }

        }

        public static void Add<T>(string key, T value, TimeSpan slidingExpiration)
        {
            if (value == null)
            {
                return;
            }

            if (slidingExpiration.TotalSeconds <= 0)
            {
                Remove(key);

                return;
            }

            try
            {
                if (pool != null)
                {
                    using (var r = pool.GetClient())
                    {
                        if (r != null)
                        {
                            r.SendTimeout = 1000;
                            r.Set(key, value, slidingExpiration);
                        }
                    }
                }
            }
            catch (Exception ex)
            {
                string msg = string.Format("{0}:{1}发生异常!{2}", "cache", "存储", key);
            }

        }

        public static T Get<T>(string key)
        {
            if (string.IsNullOrEmpty(key))
            {
                return default(T);
            }

            T obj = default(T);

            try
            {
                if (pool != null)
                {
                    using (var r = pool.GetClient())
                    {
                        if (r != null)
                        {
                            r.SendTimeout = 1000;
                            obj = r.Get<T>(key);
                        }
                    }
                }
            }
            catch (Exception ex)
            {
                string msg = string.Format("{0}:{1}发生异常!{2}", "cache", "获取", key);
            }

            return obj;
        }

        public static void Remove(string key)
        {
            try
            {
                if (pool != null)
                {
                    using (var r = pool.GetClient())
                    {
                        if (r != null)
                        {
                            r.SendTimeout = 1000;
                            r.Remove(key);
                        }
                    }
                }
            }
            catch (Exception ex)
            {
                string msg = string.Format("{0}:{1}发生异常!{2}", "cache", "删除", key);
            }

        }

        public static bool Exists(string key)
        {
            try
            {
                if (pool != null)
                {
                    using (var r = pool.GetClient())
                    {
                        if (r != null)
                        {
                            r.SendTimeout = 1000;
                            return r.ContainsKey(key);
                        }
                    }
                }
            }
            catch (Exception ex)
            {
                string msg = string.Format("{0}:{1}发生异常!{2}", "cache", "是否存在", key);
            }

            return false;
        }
    }
}

　　说明：RedisCacheHelper 使用的是客户端链接池模式，这样的存取效率应该是最高的。同时也更方便的支持读写分离，均衡负载。

　　3. 配置文件

    <!-- redis Start   -->
    <add key="SessionExpireMinutes" value="180" />
    <add key="redis_server_session" value="127.0.0.1:6379" />
    <add key="redis_max_read_pool" value="3" />
    <add key="redis_max_write_pool" value="1" />
    <!--redis end-->

　

　　4. 测试程序调用

class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Redis写入缓存：zhong");

            RedisCacheHelper.Add("zhong", "zhongzhongzhong", DateTime.Now.AddDays(1));

            Console.WriteLine("Redis获取缓存：zhong");

            string str3 = RedisCacheHelper.Get<string>("zhong");

            Console.WriteLine(str3);

            Console.WriteLine("Redis获取缓存：nihao");
            string str = RedisCacheHelper.Get<string>("nihao");
            Console.WriteLine(str);

            Console.WriteLine("Redis获取缓存：wei");
            string str1 = RedisCacheHelper.Get<string>("wei");
            Console.WriteLine(str1);

            Console.ReadKey();
        }
    }

　　

　　5. 输出结果