static void

using System;
using System.Web;
 
/// <summary>
/// Strongly typed access to asp session
/// </summary>
public static class SessionManager
{
    /// <summary>
    /// Gets the value or default of an object (eg Cache, Session, ViewState)
    /// </summary>
    /// <typeparam name="T">The expected type</typeparam>
    /// <param name="o">The object</param>
    /// <returns></returns>
    private static T GetValueOrDefault<T>(object o)
    {
        if (o != null && o is T) return (T)o; //value if exists
        return default(T); //default
    }
 
    /// <summary>
    /// Gets the session value or default (generic version- just pass in the key string and specify the type)
    /// </summary>
    /// <typeparam name="T">The expected type</typeparam>
    /// <param name="key">The session key</param>
    /// <returns></returns>
    public static T GetSessionValueOrDefault<T>(string key)
    {
        object o = HttpContext.Current.Session[key];
        return GetValueOrDefault<T>(o); //default
    }
 
    /// <summary>
    /// Gets or sets the user birthday (example). Try to keep all session access behind strongly typed properties of SessionManager like this.
    /// </summary>
    /// <value>The user birthday.</value>
    public static DateTime UserBirthday
    {
        get
        {
            return GetValueOrDefault<DateTime>(HttpContext.Current.Session["UserBirthday"]);
        }
        set { HttpContext.Current.Session.Add("UserBirthday", value); }
    }
}

//FOR 2.0 ONLY. in 3.5 this is in System.Core

public delegate TResult Func<TResult>();

 

/// <summary>

/// Generic storage in cache (essentially a wrapper around your data access function)

/// </summary>

public static T LoadCache<T>(string key, Func<T> func) where T : class

{

    Cache Cache = HttpRuntime.Cache;

    T result = Cache[key] as T;

    if (result == null)

    {

        result = func();

        Cache[key] = result;

    }

    return result;

}

 

public static IList<Customer> GetCustomers()

{

    //3.5

    //return Load("GetCustomers", () => DataBroker.GetCustomers());

    //2.0

    return LoadCache<IList<Customer>>("GetCustomers" + year,

                       delegate()

                       {

                           return DataBroker.GetCustomers();

                       });

}