引用類庫1.Install-Package Microsoft.Extensions.Caching.Memory MemoryCacheOptions 緩存配置1.ExpirationScanFrequency 獲取或設(shè)置對過期項的連續(xù)掃描之間的最短時間間隔 2.SizeLimit 緩存是沒有大小的的，此值設(shè)置緩存的份數(shù) 3.CompactionPercentage 獲取或設(shè)置在超過最大大小時壓縮緩存的數(shù)量，優(yōu)先壓縮優(yōu)先級較低的緩存，0.2代表20% services.AddMemoryCache(options => { // 緩存最大為100份 //##注意netcore中的緩存是沒有單位的，緩存項和緩存的相對關(guān)系 options.SizeLimit = 2; //緩存滿了時候壓縮20%的優(yōu)先級較低的數(shù)據(jù) options.CompactionPercentage = 0.2; //兩秒鐘查找一次過期項 options.ExpirationScanFrequency = TimeSpan.FromSeconds(2); });
MemoryCacheEntryOptions 單個緩存項配置1.AbsoluteExpiration 絕對過期時間 2. AbsoluteExpirationRelativeToNow 相對于現(xiàn)在的絕對過期時間 3.SlidingExpiration 滑動過期時間，在時間段范圍內(nèi) 緩存被再次訪問，過期時間將會被重置 4.Priority 優(yōu)先級 5.Size 緩存份數(shù) public bool Add(string key, object value, int ExpirtionTime = 20) { if (!string.IsNullOrEmpty(key)) { MemoryCacheEntryOptions cacheEntityOps = new MemoryCacheEntryOptions() { //滑動過期時間 20秒沒有訪問則清除 SlidingExpiration = TimeSpan.FromSeconds(ExpirtionTime), //設(shè)置份數(shù) Size = 1, //優(yōu)先級 Priority = CacheItemPriority.Low, }; //過期回掉 cacheEntityOps.RegisterPostEvictionCallback((keyInfo, valueInfo, reason, state) => { Console.WriteLine($"回調(diào)函數(shù)輸出【鍵:{keyInfo},值:{valueInfo},被清除的原因:{reason}】"); }); _cache.Set(key, value, cacheEntityOps); } return true; } 完整代碼1.接口 public interface ICacheService { /// <summary> /// 新增 /// </summary> /// <param name="key"></param> /// <param name="value"></param> /// <param name="ExpirtionTime"></param> /// <returns></returns> bool Add(string key, object value, int ExpirtionTime = 20); /// <summary> /// 獲取 /// </summary> /// <param name="key"></param> /// <returns></returns> string GetValue(string key); /// <summary> /// 驗證緩存項是否存在 /// </summary> /// <param name="key">緩存Key</param> /// <returns></returns> bool Exists(string key); /// <summary> /// 移除 /// </summary> /// <param name="key"></param> /// <returns></returns> bool Remove(string key); } 2. 實現(xiàn) ICacheService /// <summary> /// 緩存接口實現(xiàn) /// </summary> public class MemoryCacheService : ICacheService { protected IMemoryCache _cache; public MemoryCacheService(IMemoryCache cache) { _cache = cache; } public bool Add(string key, object value, int ExpirtionTime = 20) { if (!string.IsNullOrEmpty(key)) { MemoryCacheEntryOptions cacheEntityOps = new MemoryCacheEntryOptions() { //滑動過期時間 20秒沒有訪問則清除 SlidingExpiration = TimeSpan.FromSeconds(ExpirtionTime), //設(shè)置份數(shù) Size = 1, //優(yōu)先級 Priority = CacheItemPriority.Low, }; //過期回掉 cacheEntityOps.RegisterPostEvictionCallback((keyInfo, valueInfo, reason, state) => { Console.WriteLine($"回調(diào)函數(shù)輸出【鍵:{keyInfo},值:{valueInfo},被清除的原因:{reason}】"); }); _cache.Set(key, value, cacheEntityOps); } return true; } public bool Remove(string key) { if (string.IsNullOrEmpty(key)) { return false; } if (Exists(key)) { _cache.Remove(key); return true; } return false; } public string GetValue(string key) { if (string.IsNullOrEmpty(key)) { return null; } if (Exists(key)) { return _cache.Get(key).ToString(); } return null; } public bool Exists(string key) { if (string.IsNullOrEmpty(key)) { return false; } object cache; return _cache.TryGetValue(key, out cache); } }
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