GridView用資料來源控制元件和用DataTable作為資料來源的不同

1.使用資料來源控制元件可以自動做排序分頁，不需要多餘程式碼，可是由於自動繫結太多操作，反而覺得很不靈活
前臺：

<asp:GridViewID="gv_test"DataSourceID="ds_test"AllowPaging="True" PageSize="10"runat="server">

...

</asp:GridView>

<asp:SqlDataSource  runat="server" ID="ds_test" SelectCommand="select * from test" ConnectionString="...">

2.使用DataTable為資料來源會發現排序，分頁包括修改，取消等操作都需要手動實現

前臺：

 <asp:GridView ID="gv_test"  runat="server" 
            OnRowCommand="gv_test_RowCommand"  OnRowUpdating="gv_test_RowUpdating"  OnRowEditing ="gv_test_RowEditing"
            OnRowCancelingEdit ="gv_test_RowCancelingEdit" OnPageIndexChanging ="gv_test_PageIndexChanging"  
            AllowPaging="True"  PageSize="10" AllowSorting="True" >

...

</asp:GridView >

後臺：

Page_Load: gv_test.SortExpression總是為空，只好將排序字串儲存在新建的屬性裡    

gv_test.Attributes.Add("Sort", "lastUpdateDate desc")

Protected Sub bind()

   gv_test.DataSource = getDataTable_bySQL("select * from test order by "+gv_test.Attributes("Sort"))
   gv_test.DataBind()

End Sub

DataView比DatatTable功能強大些，可以拿到資料後進行排序。當SQL Server的ntext列不支援order by時候，用DataView可以解決問題，如下：

Protected Sub bind()

   gv_test.DataSource = getDataTable_bySQL("select * from test")

   Dim dv As DataView = New DataView(getTableData_bySQL("select * from test"))
   

   dv.Sort=gv_test.Attributes("Sort")

   gv_test.DataSource=dv
   gv_test.DataBind()

End Sub

    Protected Sub gv_test_Sorting(ByVal sender As Object, ByVal e As GridViewSortEventArgs) Handles gv_test.Sorting
        gv_test.EditIndex = -1
        If gv_test.Attributes("Sort") = e.SortExpression + " desc" Then
            gv_test.Attributes("Sort") = e.SortExpression
        Else
            gv_test.Attributes("Sort") = e.SortExpression + " desc"
        End If
        bind()
    End Sub
    Protected Sub gv_test_PageIndexChanging(ByVal sender As Object, ByVal e As GridViewPageEventArgs)
        gv_test.PageIndex = e.NewPageIndex
        gv_test.EditIndex = -1
        bind()
    End Sub
    Protected Sub gv_test_RowCancelingEdit(ByVal sender As System.Object, ByVal e As System.Web.UI.WebControls.GridViewCancelEditEventArgs)
        gv_test.EditIndex = -1
        bind()
    End Sub
    Protected Sub gv_test_RowUpdating(ByVal sender As System.Object, ByVal e As System.Web.UI.WebControls.GridViewUpdateEventArgs) Handles gv_test.RowUpdating
        gv_test.EditIndex = -1
    End Sub
    Public Sub gv_test_RowEditing(ByVal sender As System.Object, ByVal e As System.Web.UI.WebControls.GridViewEditEventArgs)
        gv_test.EditIndex = e.NewEditIndex
        bind()
    End Sub