主题：这段填充数据的代码错在何处？

Dim dt As DataTable = DataTables("临时报名表")
Dim qus As List(Of String)= dt.GetUniqueValues("", "区")
Dim xxs As List(Of String)= dt.GetUniqueValues("", "学校")
For Each qu As String In qus
    For Each xx As String In xxs
        Dim flt As String  = "区 = '" & qu & "' And 学校 = '" & xx & "'"
        If DataTables("报名表").Find(flt) Is Nothing Then
            Dim f As New Filler
            f.filter = flt
            f.SourceTable = dt '指定数据来源
            f.DataTable = DataTables("报名表") '指定数据接收表
            f.Fill() '填充数据
        End If
    Next
Next

帖子标题，最好简单描述一下问题，不要总是两个字“求助”