前言：要使用redis，首先电脑要先下载安装redis，下载安装可以看我上一篇文章 https://blog.csdn.net/weixin_44442366/article/details/124205310
我们用StackExchange.Redis包在.NET Core中使用Redis实现缓存，如果想可视化查看redis缓存里面的数据可以安装RedisDesktopManager。

一、在NuGet搜索安装StackExchange.Redis包

二、在appsettings.json文件里面添加Redis相关配置信息：

 "Redis": {
    "Default": {
      "Connection": "127.0.0.1:6379,password=888", //redis连接地址，端口号,密码
      "InstanceName": "local", //实例名
      "DefaultDB": "8", //Db8数据库
    }

三、创建Redis帮助类

创建RedisHelper类，代码如下：

using StackExchange.Redis;
using System.Collections.Concurrent;

namespace RedisDemo.redis
{
    public class RedisHelper : IDisposable
    {
        //连接字符串
        private string _connectionString;
        //实例名称
        private string _instanceName;
        //默认数据库
        private int _defaultDB;

        private ConcurrentDictionary<string, ConnectionMultiplexer> _connections;
        public RedisHelper(string connectionString, string instanceName,  int defaultDB = 0)
        {
            _connectionString = connectionString;
            _instanceName = instanceName;
            _defaultDB = defaultDB;
            _connections = new ConcurrentDictionary<string, ConnectionMultiplexer>();
        }

        /// <summary>
        /// 获取ConnectionMultiplexer
        /// </summary>
        /// <returns></returns>
        private ConnectionMultiplexer GetConnect()
        {
            return _connections.GetOrAdd(_instanceName, p => ConnectionMultiplexer.Connect(_connectionString));
        }

        /// <summary>
        /// 获取数据库
        /// </summary>
        /// <param name="configName"></param>
        /// <param name="db">默认为0：优先代码的db配置，其次config中的配置</param>
        /// <returns></returns>
        public IDatabase GetDatabase()
        {
            return GetConnect().GetDatabase(_defaultDB);
        }

        public IServer GetServer(string configName = null, int endPointsIndex = 0)
        {
            var confOption = ConfigurationOptions.Parse(_connectionString);
            return GetConnect().GetServer(confOption.EndPoints[endPointsIndex]);
        }

        public ISubscriber GetSubscriber(string configName = null)
        {
            return GetConnect().GetSubscriber();
        }
        public void Dispose()
        {
            if (_connections != null && _connections.Count > 0)
            {
                foreach (var item in _connections.Values)
                {
                    item.Close();
                }
            }
        }
    }
}

四、添加服务依赖项

在Program.cs类添加服务依赖

//redis缓存
var section =builder.Configuration.GetSection("Redis:Default");
//连接字符串
string _connectionString = section.GetSection("Connection").Value;
//实例名称
string _instanceName = section.GetSection("InstanceName").Value;
//默认数据库 
int _defaultDB = int.Parse(section.GetSection("DefaultDB").Value ?? "0");
builder.Services.AddSingleton(new RedisHelper(_connectionString, _instanceName, _defaultDB));

五、测试使用， 在控制器接口中使用

using Microsoft.AspNetCore.Mvc;
using RedisDemo.redis;
using StackExchange.Redis;

namespace RedisDemo.Controllers
{
    [Route("api/[controller]")]
    [ApiController]
    public class RedisTestController : ControllerBase
    {
        private readonly IDatabase _redis;
        public RedisTestController(RedisHelper client)
        {
            _redis = client.GetDatabase();
        }
        [HttpGet("test")]
        public string Get()
        {
            // 往Redis里面存入数据
            _redis.StringSet("Name", "hehe");
            // 从Redis里面取数据
            string name = _redis.StringGet("Name");
            return name;
        }
    }
}

api测试返回成功

用命令查看redis数据库正常存入，select 8 进入第8个库，keys *： 列出所有key，get Name：查看Name键的值

用可视化工具RedisDesktopManager查看