HttpContext.Current.Session 未将对象引用设置到对象的实例

改程序时候出了个错误，HttpContext.Current.Session　不能取值，报错：未将对象引用设置到对象的实例

查看代码发现“　Private connOF As DBSearch = New DBSearch("OF")　”　初始化在Page_load之前，作为全局定义的。 （DBSearch为数据库访问类，获取SESSION的一些字段等）

Imports System.Data
Imports System.Data.SqlClient
Imports System.String
Imports System.Timers
    Partial Class lianxi
        Inherits System.Web.UI.Page
        Private param As Hashtable
    'Private conn As DBSearch = New DBSearch()
    Private connOF As DBSearch = New DBSearch("OF")
    Private flag As Boolean
    Private type As String

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

        type = Me.Request.QueryString("type")
        Dim id As String = Me.Request.QueryString("id")

 将Private connOF As DBSearch = New DBSearch("OF")　这句放在各个事件中去，就没有错误了