1. 打开NuGet管理器搜索redis，安装：“StackExchange.Redis”

2. 配置 Web.config 文件

  <connectionStrings>
    <add name="connStr" connectionString="mongodb://127.0.0.1:27017/mydb01" />      <!-- 在有些版本里面如果不带上数据库名称会出错 -->
    <add name="redis" connectionString="127.0.0.1"/>          <!-- Redis -->
  </connectionStrings>

3. 添加 Redis.cs 文件

    public class Redis
    {
        private static readonly string redisConn = ConfigurationManager.ConnectionStrings["redis"].ToString();

        #region 常用的数据库
        public static IDatabase Top { get; } = GetDb(0);
        public static IDatabase TopOauth { get; } = GetDb(1);
        public static IDatabase TopService { get; } = GetDb(2);
        #endregion
　　     /// <summary>
        /// 获取数据库
        /// </summary>
        /// <param name="dbnumber"></param>
        /// <returns></returns>
        public static IDatabase GetDatabase(int dbnumber)
        {
            ConnectionMultiplexer server = ConnectionMultiplexer.Connect(redisConn);
            return server.GetDatabase(dbnumber);
        }
    }

    /// <summary>
    /// Redis缓存扩展：保存、获取、删除（不过其实好像没有用到，引用的框架了好像已经带有这个方法了）
    /// </summary>
    public static class RedisExt
    {
        /// <summary>
        /// 保存一个对象（string类型）
        /// </summary>
        /// <param name="cache"></param>
        /// <param name="key"></param>
        /// <param name="value"></param>
        /// <param name="experation"></param>
        /// <returns></returns>
        public static async Task<bool> SetAsync(this IDatabaseAsync cache, string key, object value,TimeSpan experation)
        {
            return await cache.StringSetAsync(key, JsonConvert.SerializeObject(value), experation);
        }

        /// <summary>
        /// 获取一个对象
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="cache"></param>
        /// <param name="key"></param>
        /// <returns></returns>
        public static async Task<T> GetTAsync<T>(this IDatabaseAsync cache,string key)
        {
            var value = await cache.StringGetAsync(key).ConfigureAwait(false);
            if(!value.IsNull)
            {
                return JsonConvert.DeserializeObject<T>(value);
            }
            else
            {
                return default(T);
            }
        }

        /// <summary>
        /// 删除一个对象
        /// </summary>
        /// <param name="cache"></param>
        /// <param name="key"></param>
        /// <returns></returns>
        public static async Task<bool> DelAsync(this IDatabaseAsync cache,string key)
        {
            return await cache.KeyDeleteAsync(key).ConfigureAwait(false);
        }
    }

4. Redis 的使用

        public async Task GetCodeAsync(string mobile)
        {
            string id = ObjectId.GenerateNewId().ToString();
            var text = GetRandomString(6);      //验证码

            //存储缓存（形式是这种形式，但实际应用不一定要这样用，要灵活运用key的形式）
            await Redis.TopOauth.StringSetAsync($"SMSCODE:{mobile}", text.ToLower(), new TimeSpan(0, 5, 0));

            //发送手机验证码
        }

        /// <summary>
        /// 生成随机字符串
        /// </summary>
        /// <param name="length"></param>
        /// <returns></returns>
        private static string GetRandomString(int length)
        {
            return Guid.NewGuid().ToString("N").Substring((32 - length), length);
        }

　　这里只使用了保存，还有获取和删除，要注意key要对应。