下面的代码，是先获取本月所以订单，然后在筛选出选择日期的订单。是否有错，感觉有些臃肿，有可以优化高效一些吗？谢谢!

Dim y As Integer = Date.Today.Year
Dim m As Integer = Date.Today.Month
Dim dt1 As New Date(y, m, 1)
Dim dt2 As New Date(y, m, Date.DaysInMonth(y, m)) \'获取本月的最后一天
Dim Filter As String
Filter = "截止日期 >= \'" & dt1 & "\' And 截止日期 <= \'" & dt2 & "\'"
DataTables("派工").LoadFilter = Filter
DataTables("派工").Load()

Tables("派工").Filter = "截止日期 = \'" & e.Sender.Value & "\'"
Static lst As List(of Date) \'定义一个静态集合变量,用于存储选择的截止日期
If lst Is Nothing Then
    lst = New List(of Date)
End If
If ModifierKey <> Keys.Control Then \'如果没有按下Ctrl键
    lst.Clear() \'清除以前的截止日期
End If
If lst.Contains(e.Sender.Value) = False Then \'如果集合不包括按下的截止日期
    lst.Add(e.Sender.Value) \'则向集合添加此截止日期
End If
If lst.Count = 1 Then \'如果只选择了一个截止日期,则直接筛选此截止日期的派工
    Tables("派工").Filter = "截止日期 = \'" & e.Sender.Value & "\'"
Else \'否则用In运算符筛选选定的多个截止日期的派工
    Dim v As String
    For i As Integer = 0 To lst.Count - 1
        v = v & "\'" & lst(i) & "\',"
    Next
    v = v.Trim(",")
    Tables("派工").Filter = "截止日期 In (" & v & ")"
End If
Tables("派工").Filter &= " and 时段 <> \'5取消\'"

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