主题：求代码

If e.DataCol.Name =  "箱数" Then
    If e.Datarow.IsNull("箱数") Then
        e.datarow("开始箱号") = Nothing
        e.datarow("结束箱号") = Nothing
    Else
        Dim dr As DataRow = DataTables("装箱单").Find("[IO] = '" & e.datarow("IO") & "' And [口岸] = '" & e.datarow("口岸") & "' And [结束箱号] > 0","_identify Desc")
        if dr IsNot Nothing Then
            e.datarow("开始箱号") = dr("结束箱号")+1
        Else 
            e.datarow("开始箱号")  = 1
        End if
    End if
End if