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在Core中不能使用原HttpRuntime.Cache缓存，改为MemoryCache（Microsoft.Extensions.Caching.Memory）.
现MemoryCache新版为2.0.1，于原HttpRuntime.Cache扩展方法基本相同，但里面没有查询全部键(key) 的扩展，要想查询可通过反射查找
代码如下:
我要评论 public List<string> GetCacheKeys()
{
const BindingFlags flags = BindingFlags.Instance | BindingFlags.NonPublic;
var entries = Cache.GetType().GetField("_entries", flags).GetValue(Cache);
var cacheItems = entries as IDictionary;
var keys = new List<string>();
if (cacheItems == null) return keys;
foreach (DictionaryEntry cacheItem in cacheItems)
{
keys.Add(cacheItem.Key.ToString());
}
return keys;
}
这样我们就能获取到全部的键.
整体MemoryCacheHelper类如下:
public class MemoryCacheHelper
{
private static readonly MemoryCache Cache = new MemoryCache(new MemoryCacheOptions());
/// <summary>
/// 验证缓存项是否存在
/// </summary>
/// <param name="key">缓存Key</param>
/// <returns></returns>
public bool Exists(string key)
{
if (key == null)
throw new ArgumentNullException(nameof(key));
return Cache.TryGetValue(key, out _);
}
/// <summary>
/// 添加缓存
/// </summary>
/// <param name="key">缓存Key</param>
/// <param name="value">缓存Value</param>
/// <param name="expiresSliding">滑动过期时长（如果在过期时间内有操作，则以当前时间点延长过期时间）</param>
/// <param name="expiressAbsoulte">绝对过期时长</param>
/// <returns></returns>
public bool Set(string key, object value, TimeSpan expiresSliding, TimeSpan expiressAbsoulte)
{
if (key == null)
throw new ArgumentNullException(nameof(key));
if (value == null)
throw new ArgumentNullException(nameof(value));
Cache.Set(key, value,
new MemoryCacheEntryOptions().SetSlidingExpiration(expiresSliding)
.SetAbsoluteExpiration(expiressAbsoulte));
return Exists(key);
}
/// <summary>
/// 添加缓存
/// </summary>
/// <param name="key">缓存Key</param>
/// <param name="value">缓存Value</param>
/// <param name="expiresIn">缓存时长</param>
/// <param name="isSliding">是否滑动过期（如果在过期时间内有操作，则以当前时间点延长过期时间）</param>
/// <returns></returns>
public bool Set(string key, object value, TimeSpan expiresIn, bool isSliding = false)
{
if (key == null)
throw new ArgumentNullException(nameof(key));
if (value == null)
throw new ArgumentNullException(nameof(value));
Cache.Set(key, value,
isSliding
? new MemoryCacheEntryOptions().SetSlidingExpiration(expiresIn)
: new MemoryCacheEntryOptions().SetAbsoluteExpiration(expiresIn));
return Exists(key);
}
#region 删除缓存
/// <summary>
/// 删除缓存
/// </summary>
/// <param name="key">缓存Key</param>
/// <returns></returns>
public void Remove(string key)
{
if (key == null)
throw new ArgumentNullException(nameof(key));
Cache.Remove(key);
}
/// <summary>
/// 批量删除缓存
/// </summary>
/// <returns></returns>
public void RemoveAll(IEnumerable<string> keys)
{
if (keys == null)
throw new ArgumentNullException(nameof(keys));
keys.ToList().ForEach(item => Cache.Remove(item));
}
#endregion
#region 获取缓存
/// <summary>
/// 获取缓存
/// </summary>
/// <param name="key">缓存Key</param>
/// <returns></returns>
public T Get<T>(string key) where T : class
{
if (key == null)
throw new ArgumentNullException(nameof(key));
return Cache.Get(key) as T;
}
/// <summary>
/// 获取缓存
/// </summary>
/// <param name="key">缓存Key</param>
/// <returns></returns>
public object Get(string key)
{
if (key == null)
throw new ArgumentNullException(nameof(key));
return Cache.Get(key);
}
/// <summary>
/// 获取缓存集合
/// </summary>
/// <param name="keys">缓存Key集合</param>
/// <returns></returns>
public IDictionary<string, object> GetAll(IEnumerable<string> keys)
{
if (keys == null)
throw new ArgumentNullException(nameof(keys));
var dict = new Dictionary<string, object>();
keys.ToList().ForEach(item => dict.Add(item, Cache.Get(item)));
return dict;
}
#endregion
/// <summary>
/// 删除所有缓存
/// </summary>
public void RemoveCacheAll()
{
var l = GetCacheKeys();
foreach (var s in l)
{
Remove(s);
}
}
/// <summary>
/// 删除匹配到的缓存
/// </summary>
/// <param name="pattern"></param>
/// <returns></returns>
public void RemoveCacheRegex(string pattern)
{
IList<string> l = SearchCacheRegex(pattern);
foreach (var s in l)
{
Remove(s);
}
}
/// <summary>
/// 搜索 匹配到的缓存
/// </summary>
/// <param name="pattern"></param>
/// <returns></returns>
public IList<string> SearchCacheRegex(string pattern)
{
var cacheKeys = GetCacheKeys();
var l = cacheKeys.Where(k => Regex.IsMatch(k, pattern)).ToList();
return l.AsReadOnly();
}
/// <summary>
/// 获取所有缓存键
/// </summary>
/// <returns></returns>
public List<string> GetCacheKeys()
{
const BindingFlags flags = BindingFlags.Instance | BindingFlags.NonPublic;
var entries = Cache.GetType().GetField("_entries", flags).GetValue(Cache);
var cacheItems = entries as IDictionary;
var keys = new List<string>();
if (cacheItems == null) return keys;
foreach (DictionaryEntry cacheItem in cacheItems)
{
keys.Add(cacheItem.Key.ToString());
}
return keys;
}
}
Startup.cs文件public void ConfigureServices(IServiceCollection services)方法注册MemoryCache
services.AddMemoryCache();
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