接着上一篇内容,下面处理webapi宿主到windows服务中时,简单的缓存类处理:
using System;
using System.Collections;
using System.Web;
using System.Web.Caching;
namespace aaaaa.Api.Business
{
/// <summary>
/// 缓存类
/// </summary>
public class CacheHelper
{
/// <summary>
/// 增加一个缓存对象
/// </summary>
/// <param name="strKey">键值名称</param>
/// <param name="valueObj">被缓存对象</param>
/// <param name="durationMin">缓存失效时间(默认为5分钟)</param>
/// <param name="cachePriority">保留优先级(枚举数值)</param>
/// <returns>缓存写入是否成功true 、false</returns>
public static bool InsertCach(string strKey, object valueObj, int durationMin,
CacheItemPriority cachePriority = CacheItemPriority.Default)
{
TimeSpan ts;
if (!string.IsNullOrWhiteSpace(strKey) && valueObj != null)
{
//onRemove是委托执行的函数,具体方法看下面的onRemove(...)
CacheItemRemovedCallback callBack = new CacheItemRemovedCallback(onRemove);
ts = durationMin == 0 ? new TimeSpan(0, 5, 0) : new TimeSpan(0, durationMin, 0);
//HttpContext.Current.Cache.Insert(
HttpRuntime.Cache.Insert(
strKey,
valueObj,
null,
DateTime.Now.Add(ts),
Cache.NoSlidingExpiration,
cachePriority,
callBack
);
return true;
}
else
{
return false;
}
}
/// <summary>
/// 判断缓存对象是否存在
/// </summary>
/// <param name="strKey">缓存键值名称</param>
/// <returns>是否存在true 、false</returns>
public static bool IsExist(string strKey)
{
//return HttpContext.Current.Cache[strKey] != null;
return HttpRuntime.Cache.Get(strKey) != null;
}
/// <summary>
/// 读取缓存对象
/// </summary>
/// <param name="strKey">缓存键值名称</param>
/// <returns>缓存对象,objec类型</returns>
public static object GetCache(string strKey)
{
//if (HttpContext.Current.Cache[strKey] != null)
if (IsExist(strKey))
{
object obj = HttpRuntime.Cache.Get(strKey);
return obj ?? null;
}
else
{
return null;
}
}
/// <summary>
/// 移除缓存对象
/// </summary>
/// <param name="strKey">缓存键值名称</param>
public static void Remove(string strKey)
{
//if (HttpContext.Current.Cache[strKey] != null)
if (IsExist(strKey))
{
HttpRuntime.Cache.Remove(strKey);
}
}
/// <summary>
/// 清除所有缓存
/// </summary>
public static void Clear()
{
IDictionaryEnumerator enu = HttpRuntime.Cache.GetEnumerator();
while (enu.MoveNext())
{
Remove(enu.Key.ToString());
}
}
public static CacheItemRemovedReason reason;
/// <summary>
/// 此方法在值失效之前调用,可以用于在失效之前更新数据库,或从数据库重新获取数据
/// </summary>
/// <param name="strKey"></param>
/// <param name="obj"></param>
/// <param name="reason"></param>
private static void onRemove(string strKey, object obj, CacheItemRemovedReason r)
{
reason = r;
}
//...
}
}