主题：[求助]请教：要实现以下结果，代码该怎么样优化？【已结】

Dim qujian1 As WinForm.TextBox = e.Form.Controls("TextBox1")
If qujian1.Value Is Nothing Then
    MessageBox.Show("请至少设置一个区间!","提示",MessageBoxButtons.OK,MessageBoxIcon.Error)
Else
    Dim idx As Integer
    For i As Integer = 4 To 1 Step -1
        Dim txt As WinForm.TextBox = e.Form.controls("Textbox" & i)
        If txt.text > "" Then
            idx = i
            Exit For
        End If
    Next

    For Each dr As DataRow In DataTables("表B").Select("")
        For i As Integer = idx To 1 Step -1
            Dim txt As WinForm.TextBox = e.Form.controls("Textbox" & i)
            If txt.text > "" Then
                If i = idx Then
                    If dr("分数") >= val(txt.Text) Then
                        dr("等级") = txt.text & "分以上"
                        Exit For
                    End If
                Else
                    If dr("分数") >= val(txt.Text) Then
                        dr("等级") = txt.text & " - " & e.form.controls("Textbox" & i+1).Text & "分"
                        Exit For
                    ElseIf i = 1 Then
                        If dr("分数") <= val(txt.Text) Then
                            dr("等级") = txt.text & "分以下"
                            Exit For
                        End If
                    End If
                End If
            End If
        Next
    Next
End If