个人测试环境为：Asp.net coe 3.1 WebApi
1：封装自定义的cacheHelper帮助类，部分代码
1 public static void SetCacheByFile<T>(string key, T model) 2 { 3 using (ICacheEntry entry = CreateInstans().CreateEntry(key)) 4 { 5 entry.Value = model; 6 string filepath = System.IO.Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "cachefile.txt"); 7 System.IO.FileInfo fileInfo = new System.IO.FileInfo(filepath); 8 entry.AddExpirationToken(new Microsoft.Extensions.FileProviders.Physical.PollingFileChangeToken(fileInfo)); 9 } 10 }
2：在startUp类中 注册方法：
services.AddMemoryCache();//注册使用缓存
3：测试代码
[HttpGet, Route("DocacheByFIle")] public ApiResult DoSystemFileCacheTest() { ApiResult result = new ApiResult(); try { string time = SystemCacheHelper.GetByCache<string>("Filecache"); if (string.IsNullOrEmpty(time)) { var gettime = "你好峰哥，我是文件依赖的缓存" + DateTime.Now.ToString(); SystemCacheHelper.SetCacheByFile<string>("Filecache", gettime); time = gettime; } result.data = time; result.code = statuCode.success; result.message = "获取cache数据成功！"; } catch (Exception ex) { result.message = "发生异常:" + ex.Message; } return result; }
4：文件依赖过期的测试效果截图：
4.1:当文件没有被修改，多次刷新请求，缓存的数据没有变化，到达了效果
4.2:当文件内容有修改，重新请求接口发现缓存的数据有变化，到达了预期的效果
5： 其他的测试也ok，这里就不贴出来了，下面为全部的cacheHelper帮助类的代码：
1 using System; 2 using System.Collections.Generic; 3 using System.Linq; 4 using System.Threading.Tasks; 5 6 namespace ZRFCoreTestMongoDB.Commoms 7 { 8 using Microsoft.Extensions.Caching.Memory; 9 using Microsoft.Extensions.Options; 10 using ZRFCoreTestMongoDB.Model; 11 /// <summary> 12 /// auth @ zrf 2020-07-23 13 /// </summary> 14 public class SystemCacheHelper 15 { 16 private static IMemoryCache msCache = new MemoryCache(Options.Create(new MemoryCacheOptions())); 17 private static readonly object obj = new object(); 18 //static SystemCacheHelper() 19 //{ 20 // msCache = new MemoryCache(Options.Create(new MemoryCacheOptions())); 21 //} 22 public static IMemoryCache CreateInstans() 23 { 24 if (msCache == null) 25 { 26 lock (obj) 27 { 28 if (msCache == null) 29 { 30 msCache = new MemoryCache(Options.Create(new MemoryCacheOptions())); 31 } 32 } 33 } 34 return msCache; 35 } 36 37 /// <summary> 38 /// 滑动过期/绝对过期 39 /// </summary> 40 /// <typeparam name="T"></typeparam> 41 /// <param name="key"></param> 42 /// <param name="model"></param> 43 /// <param name="hd_ab">默认true ：绝对过期，否则滑动过期</param> 44 /// <param name="Minutes"></param> 45 public static void SetCache<T>(string key, T model, bool hd_ab = true, int minutes = 3) 46 { 47 using (ICacheEntry entry = CreateInstans().CreateEntry(key)) 48 { 49 entry.Value = model; 50 if (hd_ab) 51 { 52 entry.AbsoluteExpiration = DateTime.Now.AddMinutes(minutes); 53 } 54 else 55 { 56 entry.SlidingExpiration = TimeSpan.FromMinutes(minutes); 57 } 58 } 59 } 60 61 /// <summary> 62 /// 文件依赖过期 63 /// </summary> 64 /// <typeparam name="T"></typeparam> 65 /// <param name="key"></param> 66 /// <param name="model"></param> 67 public static void SetCacheByFile<T>(string key, T model) 68 { 69 using (ICacheEntry entry = CreateInstans().CreateEntry(key)) 70 { 71 entry.Value = model; 72 string filepath = System.IO.Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "cachefile.txt"); 73 System.IO.FileInfo fileInfo = new System.IO.FileInfo(filepath); 74 entry.AddExpirationToken(new Microsoft.Extensions.FileProviders.Physical.PollingFileChangeToken(fileInfo)); 75 } 76 } 77 78 /// <summary> 79 /// 滑动过期 80 /// </summary> 81 /// <typeparam name="T"></typeparam> 82 /// <param name="key"></param> 83 /// <param name="model"></param> 84 /// <param name="Minutes"></param> 85 public static void SetCacheSliding<T>(string key, T model, int minutes = 3) 86 { 87 using (ICacheEntry entry = CreateInstans().CreateEntry(key)) 88 { 89 entry.Value = model; 90 entry.SlidingExpiration = TimeSpan.FromMinutes(minutes); 91 } 92 } 93 94 /// <summary> 95 /// 绝对过期 96 /// </summary> 97 /// <typeparam name="T"></typeparam> 98 /// <param name="key"></param> 99 /// <param name="model"></param> 100 /// <param name="Minutes"></param> 101 public static void SetCacheAbsolute<T>(string key, T model, int Minutes = 3) 102 { 103 using (ICacheEntry entry = CreateInstans().CreateEntry(key)) 104 { 105 entry.Value = model; 106 entry.AbsoluteExpiration = DateTime.Now.AddMinutes(Minutes); 107 } 108 } 109 public static T GetByCache<T>(string key) 110 { 111 if (CreateInstans().TryGetValue(key, out T model)) 112 { 113 return model; 114 } 115 return default; 116 } 117 } 118 }
6：进一步使用到自定义的配置文件中
using System; using System.Collections.Generic; using System.Linq; using System.Threading.Tasks; namespace ZRFCoreTestMongoDB.Commoms { using ZRFCoreTestMongoDB.Model; using Microsoft.Extensions.Configuration; public class AppJsonHelper { public static JwtConfigModel InitJsonModel() { string key = "key_myjsonfilekey"; JwtConfigModel cachemodel = SystemCacheHelper.GetByCache<JwtConfigModel>(key); if (cachemodel == null) { ConfigurationBuilder builder = new ConfigurationBuilder(); var broot = builder.AddJsonFile("./configs/zrfjwt.json").Build(); cachemodel = broot.GetSection("jwtconfig").Get<JwtConfigModel>(); SystemCacheHelper.SetCacheByFile<JwtConfigModel>(key, cachemodel); } return cachemodel; } } }