If e.DataRow("第一列") = 1 Then
Dim a as string = e.DataRow("第二列")
Dim drs As List (of DataRow) = DataTables("表A").Select("第二列 like '" & a & "%'")
For Each dr As DataRow In drs
IF dr("第三列") = true thendr("第四列").Visible = True
end if
Next