C# CacheHepler Class
2979 ワード
internal class CacheHelper
{
/// <summary>
/// Insert value into the cache using
/// appropriate name/value pairs
/// </summary>
/// <typeparam name="T">Type of cached item</typeparam>
/// <param name="o">Item to be cached</param>
/// <param name="key">Name of item</param>
public static void Add<T>(T o, string key)
{
// NOTE: Apply expiration parameters as you see fit.
// In this example, I want an absolute
// timeout so changes will always be reflected
// at that time. Hence, the NoSlidingExpiration.
HttpContext.Current.Cache.Insert(
key,
o,
null,
DateTime.Now.AddMinutes(1440),
System.Web.Caching.Cache.NoSlidingExpiration);
}
/// <summary>
/// Remove item from cache
/// </summary>
/// <param name="key">Name of cached item</param>
public static void Clear(string key)
{
HttpContext.Current.Cache.Remove(key);
}
/// <summary>
/// Check for item in cache
/// </summary>
/// <param name="key">Name of cached item</param>
/// <returns></returns>
public static bool Exists(string key)
{
return HttpContext.Current.Cache[key] != null;
}
/// <summary>
/// Retrieve cached item
/// </summary>
/// <typeparam name="T">Type of cached item</typeparam>
/// <param name="key">Name of cached item</param>
/// <param name="value">Cached value. Default(T) if
/// item doesn't exist.</param>
/// <returns>Cached item as type</returns>
public static bool Get<T>(string key, out T value)
{
try
{
if (!Exists(key))
{
value = default(T);
return false;
}
value = (T) HttpContext.Current.Cache[key];
}
catch
{
value = default(T);
return false;
}
return true;
}
使用方法:
public override List<Employee> GetEmployeeList()
{
string key = ConfigurationHelper.CacheKeyEmployeeList;
List<Employee> employees = CacheHelper.Get<List<Employee>>(key);
if (employees == null)
{
employees = instance.GetEmployeeList();
CacheHelper.Add(employees, key);
}
return employees;
}