.net自定义类中Session 存值说未将对象引用设置到对象的实例
public int intUserID
{
set
{
if (value != null)
{
int intUserID;
if (int.TryParse(value.ToString(), out intUserID))
{

HttpContext.Current.Session["UserID"] = intUserID;
}

}
}
get
{

if (HttpContext.Current.Session["UserID"] == null)
{
return -1;
}
else
{
try
{
return Convert.ToInt32(HttpContext.Current.Session["UserID"].ToString());

}
catch (Exception)
{
return -1;
}
}
}
}

[解决办法]
HttpContext是不是null
HttpContext.Current是不是null
HttpContext.Current.Session["UserID"]是不是null