vb.net Linq 筛选，像 select distinct DateTable 日期数据中的年份

    Private Sub initDDLByYear(ByVal dt As DataTable)

        ddlByYear.Items.Clear()
        ddlByYear.Items.Add(New ListItem(GetGlobalResourceObject("Resource1", "All"), "0"))


        If Not dt Is Nothing Then
            Dim years = (From r In dt.AsEnumerable
                    Select DateTime.Parse(r("create_date").ToString()).ToString("yyyy")).Distinct

            For Each y In years
                ddlByYear.Items.Add(New ListItem(y.ToString, y.ToString))
            Next

        End If
        
    End Sub