项目中我们常常会碰到一些数据,需要高频率用到但是又不会频繁变动的这类,我们就可以使用缓存把这些数据缓存起来(比如说本项目的导航数据,帖子频道数据).
我们项目中常用到有Asp.Net Core 本身提供的缓存组件MemoryCache以及第三方缓存组件Redis(当然这个不仅仅只用来做缓存工具用).
MemoryCache组件的使用:
第一步：我们在Startup类中ConfigureServices方法中添加缓存组件
services.AddMemoryCache();
第二步：我们就可以在项目中使用该缓存组件了
using System;using System.Collections.Generic;using System.Linq;using System.Threading.Tasks;using Microsoft.AspNetCore.Mvc;using Microsoft.Extensions.Caching.Memory;using MVCDemo.Core.Cache;namespace MVCDemo.Web.Controllers
{ public class CacheController : Controller
{
IMemoryCache _cache = null; public CacheController(IMemoryCache memoryCache)
{
_cache = memoryCache;
} public IActionResult Index()
{ //MemoryCache示例
string memoryCache = _cache.Get<string>("memoryCacheTest"); if (string.IsNullOrEmpty(memoryCache))
{ //添加并且设置缓存
_cache.Set<string>("memoryCacheTest", "我是memoryCacheTest缓存");
memoryCache = _cache.Get<string>("memoryCacheTest");
}
ViewData["memoryCache"] = memoryCache; return View();
}
}
}PS:在这里我们使用的构造函数注入的方式获取到了MemoryCache的实例对象
Redis缓存组件的使用:
PS:我们使用的是Windows系统上安装的Redis组件,安装教程请查看https://www.51core.net/posts/read/3048
第一步：使用Nuget添加Microsoft.Extensions.Caching.Redis组件
第二步:将Redis常用方法封装成一个服务
1.创建一个ICacheService的接口,方便缓存组件的扩展
1 using System; 2 using System.Collections.Generic; 3 using System.Text; 4 5 namespace Mango.Framework.Services.Cache 6 { 7 public interface ICacheService 8 { 9 /// <summary>10 /// 获取缓存11 /// </summary>12 /// <typeparam name="T">泛型(返回的结果类型)</typeparam>13 /// <param name="key">缓存key</param>14 /// <returns></returns>15 T Get<T>(string key) where T : new();16 /// <summary>17 /// 获取缓存18 /// </summary>19 /// <param name="key">缓存key</param>20 /// <returns></returns>21 string Get(string key);22 /// <summary>23 /// 添加缓存24 /// </summary>25 /// <param name="key">缓存key</param>26 /// <param name="value">缓存值</param>27 /// <param name="ExpirationTime">绝对过期时间(分钟)</param>28 void Add(string key, object value, int expirationTime = 20);29 /// <summary>30 /// 移除缓存31 /// </summary>32 /// <param name="key"></param>33 void Remove(string key);34 /// <summary>35 /// 更新缓存36 /// </summary>37 /// <param name="key"></param>38 /// <param name="value"></param>39 /// <param name="ExpirationTime"></param>40 void Replace(string key, object value, int expirationTime = 20);41 }42 }2.创建一个RedisCacheService类继承自ICacheService接口并且实现接口中的方法
using System;using System.Text;using Microsoft.Extensions.Caching.Redis;using Microsoft.Extensions.Caching.Distributed;using Newtonsoft.Json;namespace Mango.Framework.Services.Cache
{ public class RedisCacheService:ICacheService
{ private RedisCache _redisCache = null; public RedisCacheService(RedisCacheOptions options)
{
_redisCache = new RedisCache(options);
} /// <summary>
/// 获取缓存 /// </summary>
/// <typeparam name="T">泛型(返回的结果类型)</typeparam>
/// <param name="key">缓存key</param>
/// <returns></returns>
public T Get<T>(string key) where T:new()
{ try
{ if (!string.IsNullOrEmpty(key))
{ return JsonConvert.DeserializeObject<T>(Encoding.UTF8.GetString(_redisCache.Get(key)));
} return default(T);
} catch
{ return default(T);
}
} /// <summary>
/// 获取缓存 /// </summary>
/// <param name="key">缓存key</param>
/// <returns></returns>
public string Get(string key)
{ try
{ if (!string.IsNullOrEmpty(key))
{ return Encoding.UTF8.GetString(_redisCache.Get(key));
} return string.Empty;
} catch
{ return null;
}
} /// <summary>
/// 添加缓存 /// </summary>
/// <param name="key">缓存key</param>
/// <param name="value">缓存值</param>
/// <param name="ExpirationTime">绝对过期时间(分钟)</param>
public void Add(string key,object value,int expirationTime=20)
{ if (!string.IsNullOrEmpty(key))
{
_redisCache.Set(key, Encoding.UTF8.GetBytes(JsonConvert.SerializeObject(value)), new DistributedCacheEntryOptions()
{
AbsoluteExpiration = DateTimeOffset.Now.AddMinutes(expirationTime)
});
}
} /// <summary>
/// 移除缓存 /// </summary>
/// <param name="key">缓存key</param>
public void Remove(string key)
{ if (!string.IsNullOrEmpty(key))
{
_redisCache.Remove(key);
}
} /// <summary>
/// 更新缓存 /// </summary>
/// <param name="key">缓存key</param>
/// <param name="value">缓存值</param>
/// <param name="ExpirationTime"></param>
public void Replace(string key, object value, int expirationTime = 20)
{ if (!string.IsNullOrEmpty(key))
{
_redisCache.Remove(key);
_redisCache.Set(key, Encoding.UTF8.GetBytes(JsonConvert.SerializeObject(value)), new DistributedCacheEntryOptions()
{
AbsoluteExpiration = DateTimeOffset.Now.AddMinutes(expirationTime)
});
}
}
}
}PS：该类中的构造函数负责创建Redis缓存的实例并且把相关的参数(连接字符串)传入进行连接
第三步：在Startup类中ConfigureServices添加封装的服务组件
//注册自定义服务services.AddSingleton(typeof(ICacheService), new RedisCacheService(new RedisCacheOptions()
{
Configuration = Configuration.GetSection("Cache:ConnectionString").Value,
InstanceName = Configuration.GetSection("Cache:InstanceName").Value
}));//注册到全局服务控制类中以供其它项目的使用Framework.Services.ServiceContext.RegisterServices(services);第四步:在项目中调用,示例代码如下
ICacheService cacheService = ServiceContext.GetService<ICacheService>();string cacheData = cacheService.Get("WebSiteConfigCache");到此ASP.NET CORE MVC项目中缓存的使用介绍已经完成.
作者：喻平勇