主题：跨表生成对应行

Dim dt1 As DataTable = DataTables("合同管理")
Dim dt2 As DataTable = DataTables("本期开piao")

Dim arys() As String = {"月收,两月收,季收", "月收", "", "", "月收,年收", "", "", "", "", "", "", ""}
Dim filter As String = "收租方式 in ('" & arys(Date.Today.Month-1).replace(",", "','") & "')"
msgbox(filter)
dt2.DataRows.Clear
For Each dr As DataRow In dt1.Select(filter)
    Dim ndr As DataRow = dt2.AddNew
    ndr("合同号") = dr("合同号")
    ndr("收款方式") = dr("收租方式")
Next

老师，这句Dim filter As String = "收租方式 in ('" & arys(Date.Today.Month-1).replace(",", "','") & "')"    是判断当前收租方式类型的语句，总是出现，不管是在填数据、新增行，或者是打开项目的时候，总是会出现，而且是多次，要点击多次后才可以。

如何优化啊？

1、这句代码去掉

msgbox(filter)

2、4楼的代码，单独写到一个按钮里面去，不要写在你的表事件里面啊。

老师，现在打开项目的时候，表B 的数据重新计算了一次，被原先修改后的数据替换了。

请问怎么做到，如果表B已经有此行数据，就不要再生成该条数据了？

Dim dt1 As DataTable = DataTables("合同管理")
Dim dt2 As DataTable = DataTables("本期开piao")

Dim arys() As String = {"月收,两月收,季收", "月收", "", "", "月收,年收", "", "", "", "", "", "", ""}
Dim filter As String = "收租方式 in ('" & arys(Date.Today.Month-1).replace(",", "','") & "')"

For Each dr As DataRow In dt1.Select(filter)
    Dim ndr As DataRow = dt2.Find("合同号 = '" & dr("合同号") & "'")
    If ndr Is Nothing Then ndr = dt2.AddNew
    ndr("合同号") = dr("合同号")
    ndr("收款方式") = dr("收租方式")
Next