web自定义控件 回发问题

[yanhua1987]

根据需求，我做了一个文章列表控件，有分页功能。

当我点击自定义控件中下一页(LinkButton)时，aspx页面中需要设计控件中的基本属性。运动到设置第一条属性时提示

“未将对象引用设置到对象的实例。”的错误

        ArticleListA1.CompanyID = 8    '在这里出错了。
        ArticleListA1.CategoryID = 65
        ArticleListA1.PageDatas = 1
        ArticleListA1.GoUrl = "DynamicInfo.aspx"

请问是怎么回事？高手指点下。

[yanhua1987]

<%@ Control Language="VB" AutoEventWireup="false" CodeFile="ArticleListA.ascx.vb" Inherits="ArticleListA" %>
<%@ outputcache Duration="360" VaryByCustom="browser" VaryByParam="value" %>
<asp:Label ID="lblPrompt" runat="server"></asp:Label>
<div id="wenben">
    <ul>
        <asp:Repeater ID="AllList" runat="server">
            <ItemTemplate>
                <li><a href='<%=strGoUrl %>?id=<%# DataBinder.Eval(Container.DataItem, "ID")%>'><%#IIf(DataBinder.Eval(Container.DataItem, "title").ToString.Length > 30, Left(DataBinder.Eval(Container.DataItem, "title"), 30), DataBinder.Eval(Container.DataItem, "title"))%></a>
                    <span id="time">[<%#Left(DataBinder.Eval(Container.DataItem, "publishedTime"), DataBinder.Eval(Container.DataItem, "publishedTime").ToString.Length - 9)%>]</span>
                </li>
            </ItemTemplate>
        </asp:Repeater>
    </ul>
</div>
<div id="fanye">
    [共<asp:Label ID="lbl_datasize" runat="server" ForeColor="Red">0</asp:Label>
    条] [页次<asp:Label ID="lbl_nowpage" runat="server" ForeColor="Red">0</asp:Label>
    /<asp:Label ID="lbl_pagesize" runat="server" ForeColor="#404040">0</asp:Label>
    ] [<asp:LinkButton ID="lbn_FirstPage" runat="server">首 页</asp:LinkButton>
    ] [<asp:LinkButton ID="lbn_AgoPage" runat="server">上一页</asp:LinkButton>
    ] [<asp:LinkButton ID="lbn_NextPage" runat="server">下一页</asp:LinkButton>
    ] [<asp:LinkButton ID="lbn_LastPage" runat="server">尾 页</asp:LinkButton>
    ]
</div>

控件前台代码

[yanhua1987]

Imports System
Imports System.Data
Imports System.Data.SqlClient
Partial Class ArticleListA
    Inherits System.Web.UI.UserControl
    Public strGoUrl As String = Nothing
    Private intCompanyID As Int64 = Nothing
    Private intPartID As Int64 = Nothing
    Private intDataNum As Int32 = Nothing
    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        If IsPostBack = False Then
            If strGoUrl = Nothing OrElse intCompanyID = Nothing OrElse intPartID = Nothing OrElse intDataNum = Nothing Then
                lblPrompt.Text = "数据未初始化！"
                lbn_FirstPage.Enabled = False
                lbn_AgoPage.Enabled = False
                lbn_NextPage.Enabled = False
                lbn_LastPage.Enabled = False
                Exit Sub
            End If
            Session("ascxNowPageIDA") = 0
            Call DataLoad(CType(Session("ascxNowPageIDA"), Int32))
        End If
    End Sub
    '首页
    Protected Sub lbn_FirstPage_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles lbn_FirstPage.Click
        Session("ascxNowPageIDA") = 0
        DataLoad(CType(Session("ascxNowPageIDA"), Int32))
    End Sub
    '上一页
    Protected Sub lbn_AgoPage_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles lbn_AgoPage.Click
        Session("ascxNowPageIDA") -= 1
        DataLoad(CType(Session("ascxNowPageIDA"), Int32))
    End Sub
    '下一页
    Protected Sub lbn_NextPage_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles lbn_NextPage.Click
        Session("ascxNowPageIDA") += 1
        DataLoad(CType(Session("ascxNowPageIDA"), Int32))
    End Sub
    '尾页
    Protected Sub lbn_LastPage_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles lbn_LastPage.Click
        Session("ascxNowPageIDA") = CType(lbl_pagesize.Text, Int32) - 1
        DataLoad(CType(Session("ascxNowPageIDA"), Int32))
    End Sub
    '数据读取方法
    Private Sub DataLoad(ByVal intPageNumber As Int32)
        Dim ismysql As mySql = New mySql
        Dim Pcomid As SqlParameter = New SqlParameter("@comid", intCompanyID)
        Dim Pcid As SqlParameter = New SqlParameter("@cid", intPartID)
        Dim PParameters As SqlParameter() = {Pcomid, Pcid}
        Dim strsql As String = "select ID,title,publishedTime from Article where companyID=@comid and CategoryID=@cid ORDER BY ID DESC"
        Dim isset As DataSet = New DataSet
        isset = ismysql.ExecutSearchDST(strsql, PParameters)

        Dim myPDS As PagedDataSource = New PagedDataSource
        myPDS.DataSource = isset.Tables(0).DefaultView
        '打开分页
        myPDS.AllowPaging = True
        '每页显示数据行数
        myPDS.PageSize = intDataNum
        '数据总行数
        lbl_datasize.Text = myPDS.DataSourceCount.ToString
        '数据总页数
        lbl_pagesize.Text = myPDS.PageCount
        '当前显示页
        myPDS.CurrentPageIndex = intPageNumber
        If myPDS.PageCount + 1 = intPageNumber Then
            lbl_nowpage.Text = intPageNumber
        Else
            lbl_nowpage.Text = myPDS.CurrentPageIndex + 1
        End If

        '一页时所有按钮不可用
        If myPDS.PageCount = 1 OrElse myPDS.PageCount = 0 Then
            lbn_FirstPage.Enabled = False
            lbn_AgoPage.Enabled = False
            lbn_NextPage.Enabled = False
            lbn_LastPage.Enabled = False
        End If
        '当显示第一页时，首页和上一页按钮不可用
        If myPDS.IsFirstPage Then
            lbn_FirstPage.Enabled = False
            lbn_AgoPage.Enabled = False
            lbn_NextPage.Enabled = True
            lbn_LastPage.Enabled = True
        End If
        '当显示到最后一页时，下一页和尾页按钮不可用
        If myPDS.IsLastPage Then
            lbn_FirstPage.Enabled = True
            lbn_AgoPage.Enabled = True
            lbn_NextPage.Enabled = False
            lbn_LastPage.Enabled = False
        End If
        AllList.DataSource = myPDS
        AllList.DataBind()
        ismysql.Dispose()
    End Sub
    ''' <summary>
    ''' 设置跳转的URL
    ''' </summary>
    ''' <value>设置跳转的URL</value>
    ''' <remarks></remarks>
    Public WriteOnly Property GoUrl() As String
        Set(ByVal value As String)
            strGoUrl = value
        End Set
    End Property
    ''' <summary>
    ''' 设置公司ID
    ''' </summary>
    ''' <value>设置公司ID</value>
    ''' <remarks></remarks>
    Public WriteOnly Property CompanyID() As Int64
        Set(ByVal value As Int64)
            intCompanyID = value
        End Set
    End Property
    ''' <summary>
    ''' 设置栏目ID
    ''' </summary>
    ''' <value>设置栏目ID</value>
    ''' <remarks></remarks>
    Public WriteOnly Property CategoryID() As Int64
        Set(ByVal value As Int64)
            intPartID = value
        End Set
    End Property
    ''' <summary>
    ''' 设置每页数据条数
    ''' </summary>
    ''' <value>设置每页数据条数</value>
    ''' <remarks></remarks>
    Public WriteOnly Property PageDatas() As Int32
        Set(ByVal value As Int32)
            intDataNum = value
        End Set
    End Property
End Class


后台代码