主题：怪事怎么没有写入SQL表呢？

Dim db3 As WinForm.DropDownBox = e.Form.Controls("DropBox3")
Dim dzml3 As String = db3.text
If db3.value IsNot Nothing Then
    For Each f As String In FileSys.GetFiles(dzml3)
        If f.EndsWith(".txt") Then
            Dim strs As String = FileSys.ReadAllText(f,Encoding.Default)
            strs = strs.Replace(vblf,"")
            Dim rs() As String = strs.Split(vbcr)
            For i As Integer = 3 To rs.Length - 1
                Dim cs() As String = rs(i).replace("~~","~").Split("~")
                If cs.Length = 9 Then
                    If dt.Find("客户名称 = '" & cs(1) & "'and 税号 = '" & cs(3) & "'") Is Nothing Then
                        Dim dr As DataRow = dt.Addnew()
                        dr("客户名称") = cs(1)
                        dr("税号") = cs(3)
                        dr("地址电话") = cs(4)
                        dr("银行账号") = cs(5)
                    End If
                End If
            Next
        End If
    Next
    For Each f As String In FileSys.GetFiles(dzml3)
        If f.EndsWith(".xml") Then
            Dim txt As String = FileSys.ReadAllText(f, Encoding.Default)
            Dim xmlDoc As New System.XML.XmlDocument
            xmlDoc.Loadxml(txt.Trim)
            Dim ndList  = xmlDoc.GetElementsByTagName("Row")
            For Each dr As object In ndlist
                If dr.Attributes("NSRSBH") IsNot Nothing Then
                    Dim ndr As DataRow = dt.find("客户名称 = '" & dr.Attributes("MC").value  & "' and 税号 = '" & dr.Attributes("NSRSBH").value  & "'")
                    If ndr Is Nothing Then ndr = dt.addnew
                    ndr("客户名称") = dr.GetAttribute("MC")
                    ndr("税号") = dr.GetAttribute("NSRSBH")
                    ndr("地址电话") = dr.GetAttribute("DZ")
                    ndr("银行账号")  = dr.GetAttribute("YHZH")
                End If
            Next
        End If
    Next
    dt.DeleteFor("客户名称 Is Null   And 税号 Is Null   And 地址电话 Is Null  And 银行账号 Is Null ")
End If
If dt.HasChanges Then
    dt.Save
    dt.load()
    MessageBox.Show("客户信息导入完成")
Else
    MessageBox.Show("没有导入任何客户信息")
End If