错误在那里？

Namespace aspx

Partial Class ExamPaper
    Inherits System.Web.UI.Page

#Region " Web 窗体设计器生成的代码 "

    '该调用是 Web 窗体设计器所必需的。
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()

    End Sub

    '注意: 以下占位符声明是 Web 窗体设计器所必需的。
    '不要删除或移动它。

    Private Sub Page_Init(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Init
        'CODEGEN: 此方法调用是 Web 窗体设计器所必需的
        '不要使用代码编辑器修改它。
        InitializeComponent()
    End Sub

#End Region
    Dim sqlstr As New aspx.sqllangue.sqllangue
    Dim sqlselect As String
    Private Sub errorshow()
        If Me.Session("error") <> "" Then
            Me.Response.Write(Me.Session("error"))
            Me.Response.End()
        End If
    End Sub
    Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        '在此处放置初始化页的用户代码
        loadtable()
    End Sub
    Private Sub DataGrid1_PageIndexChanged(ByVal source As Object, ByVal e As System.Web.UI.WebControls.DataGridPageChangedEventArgs) Handles DataGrid1.PageIndexChanged
        Me.Session("pageno") = e.NewPageIndex
        loadtable()
    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Me.Response.Redirect("epadd.aspx")
    End Sub

    Private Sub DataGrid1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles DataGrid1.SelectedIndexChanged
        Dim rowsid As Integer = Me.DataGrid1.CurrentPageIndex * Me.DataGrid1.PageSize + Me.DataGrid1.SelectedIndex
        Me.Session("selectid") = sqlstr.sqlds.Tables("temporary").Rows(rowsid).Item(0)
        Me.Response.Redirect("EPedit.aspx")
    End Sub

    Private Sub DataGrid1_EditCommand(ByVal source As Object, ByVal e As System.Web.UI.WebControls.DataGridCommandEventArgs) Handles DataGrid1.EditCommand
        Me.Session("shijuanid") = e.Item.Cells(0).Text
        Me.Session("shijuanname") = e.Item.Cells(1).Text
        Me.Session("shijuanstyle") = e.Item.Cells(2).Text
        Me.Session("shijuanfanwei") = e.Item.Cells(3).Text
        Me.Response.Redirect("EPtype.aspx")
    End Sub

    Private Sub DataGrid1_DeleteCommand(ByVal source As Object, ByVal e As System.Web.UI.WebControls.DataGridCommandEventArgs) Handles DataGrid1.DeleteCommand
        Dim rowsid As Integer = Val(e.Item.Cells(0).Text)
        Dim dsrowsid As Integer = sqlstr.sqlds.Tables("temporary").Rows.Count() - 1
        If sqlstr.sqlds.Tables("temporary").Rows(dsrowsid).Item(0) = rowsid Then
            Me.Session("pageno") -= 1
        End If
        sqlstr.delEP(e.Item.Cells(0).Text)
        loadtable()
    End Sub
    Public Sub loadtable()
        sqlstr.sqlconn.Close()
        sqlstr.conn()
        errorshow()

        sqlselect = "select * from exampaper order by stime DESC"
        sqlstr.sqlds.Clear()
        sqlstr.sqlselect(sqlselect)
        errorshow()
        Me.DataGrid1.DataSource = sqlstr.sqlds.Tables("temporary").DefaultView
        Me.DataGrid1.CurrentPageIndex = Me.Session("pageno")///这一行出现错误
        Me.DataGrid1.DataBind()
    End Sub
End Class

End Namespace





指定的参数已超出有效值的范围。
参数名: value
说明: 执行当前 Web 请求期间，出现未处理的异常。请检查堆栈跟踪信息，以了解有关该错误以及代码中导致错误的出处的详细信息。

异常详细信息: System.ArgumentOutOfRangeException: 指定的参数已超出有效值的范围。
参数名: value

源错误:


行 75:         errorshow()
行 76:         Me.DataGrid1.DataSource = sqlstr.sqlds.Tables("temporary").DefaultView
行 77:             Me.DataGrid1.CurrentPageIndex = Me.Session("pageno")///这一行出现错误
行 78:         Me.DataGrid1.DataBind()
行 79:     End Sub

指定的参数已超出有效值的范围。
看这句