主题：[求助]未将对象引用设置到对象的实例问题

修改代码

Dim  dr As  DataRow = e.Node.DataRow  '获取生成此节点的行
Dim Filter As String
e.Form.StopRedraw
If e.node.text <> "显示所有行" Then    

    Dim Year As  Integer = dr("年")
    Dim  Month As   Integer =  dr("月")
    Dim   Product As   String =  dr("驾驶员")
    Select Case e.Node.Level
        Case  0
            Filter ="驾驶员= '"  & Product  &  "'"
        Case  1
            Filter ="Year(出车时间) = "  &  Year &  " And 驾驶员 = '"  &  Product  &  "'"
        Case  2
            Filter ="Year(出车时间) = "  &  Year  &  " And Month(出车时间) = "  &  Month  &  " And 驾驶员 = '"  &  Product  &  "'"
    End Select
Else
    Filter = ""
End If
DataTables("派车表").LoadFilter = Filter
DataTables("派车表").Load()
e.Form.ResumeRedraw