批量删除行报错，什么情况

上传出错例子，或者贴出DataColChanged事件代码

If e.DataCol.Name = "序号" Then
    If e.NewValue = "1" Then
        e.DataRow("页号")=1
    End If
Else
   
    Select Case e.DataCol.Name
        Case "页数"
            For Each dr As DataRow In e.DataTable.Select("[_SortKey] >= " & e.DataRow("_SortKey"))
                Dim Val1 As Double = e.DataTable.Compute("Sum(页数)","[_SortKey] <= " & dr("_SortKey"))
                           
                dr("页号") = Val1
            Next
    End Select
End If

\'-----------------------------------------------------------
If e.DataCol.Name = "是否归档" Then
    If e.DataRow("是否归档") = True Then
        e.DataRow("操作员") = User.Name
        e.DataRow("归档日期") = Date.Now
        \'Else
        \'e.DataRow("取消归整人") = User.Name
        \'e.DataRow("取消归整时间")= Date.Now
    End If
End If
\'-------------------------------------------------------
Select Case e.DataCol.name
    Case "案卷号"
        If e.newvalue > "" Then
            e.DataRow("案卷号")=format(Val(e.newValue),"0000")
        End If
End Select

If e.newvalue > "" Then

改成

If e.newvalue <> Nothing Then

If e.NewValue = "1" Then

改成

If Cstr(e.NewValue) = "1" Then