/// <summary>
/// 序列化viewstate对象
/// </summary>
/// <param name="obj"></param>
/// <returns></returns>
private string SerializeObj(object obj)
{
string value = new ObjectStateFormatter().Serialize(obj);
string stateID = (DateTime.Now.Ticks + (long)value.GetHashCode()).ToString(); //产生离散的id号码
File.WriteAllText(Path.Combine(Dir.FullName, stateID), value);
Cache.Insert(stateID, value);
return(stateID);
}