主题：[求助]动态表达式合成

 Dim Filter As String
With e.Form.Controls("DateTimePicker1")
    If .Value IsNot Nothing Then
        Filter = "日期 >= '" & .Value & "' "
    End If
End With

With e.Form.Controls("DateTimePicker2")
    If .Value IsNot Nothing Then
        If Filter > "" Then
            Filter = Filter & " And "   '相\在原条件基础上添加 and
        End If
        Filter = Filter & "日期 <= '" & .Value & "' "   '添加下一个条件
    End If
End With


Dim drs1 As List(Of DataRow)
Dim drs2 As List(Of DataRow)
Dim day_delay As Integer = e.Form.Controls("NumericComboBox1").Value

Dim number_delay As Integer = e.Form.Controls("NumericComboBox2").Value

drs1 = DataTables("故障报告").Select("" & Filter & "")

请大神们帮忙看下，上面标红的代码是不是有问题，不会报错，但筛选出来的不大对，谢谢！