/// <summary>
/// 信息是否存在
/// </summary>
/// <returns></returns>
public static bool IsExist <T>(this HttpSessionStateBase session, string Key)
{
bool ret = false;
T userInfo = session.GetValue <T>(Key);
if (userInfo != null)
{
ret = true;
}
return(ret);
}
/// <summary>
/// Ensures a specific key to be either already in the ASP.NET MVC session state or to be newly created
/// </summary>
/// <typeparam name = "T">The generic type to be returned</typeparam>
/// <param name = "sessionState">The session state.</param>
/// <param name = "key">The session state key.</param>
/// <returns>The session state value.</returns>
/// <example>
/// <code>
/// public List<String> StringValues
/// {
/// get { return this.Session.Ensure<List<String>>("StringValues"); }
/// set { this.ViewState.Set("StringValues", value); }
/// }
/// </code>
/// </example>
public static T Ensure <T>(this HttpSessionStateBase sessionState, String key) where T : class, new()
{
var value = sessionState.GetValue <T>(key);
if (null == value)
{
value = new T();
sessionState[key] = value;
}
return(value);
}