コードでカスタム ページング テンプレートの使用

Private Class CustomPagerTemplate
    Implements ITemplate
    #Region "ITemplate Members"
    Public Sub InstantiateIn(ByVal container As Control) Implements ITemplate.InstantiateIn
        Dim prevButton As New HtmlButton()
        prevButton.ID = "PrevButton"
        prevButton.InnerText = "Prev"
        prevButton.Attributes("onclick") = "return PreviousPage()"
        Dim ddl As New DropDownList()
        ddl.ID = "DropDownList1"
        For i As Integer = 1 To 12
            ddl.Items.Add(i.ToString())
        Next
        ddl.Attributes("onchange") = "return IndexChanged()"
        Dim nextButton As New HtmlButton()
        nextButton.InnerText = "Next"
        nextButton.Attributes("onclick") = "return NextPage()"
        container.Controls.Add(prevButton)
        container.Controls.Add(ddl)
        container.Controls.Add(nextButton)
    End Sub
    #End Region
End Class

private class CustomPagerTemplate : ITemplate
{
        #region ITemplate Members
        public void InstantiateIn(Control container)
        {
        HtmlButton prevButton = new HtmlButton();
        prevButton.ID = "PrevButton";
        prevButton.InnerText = "Prev";
        prevButton.Attributes["onclick"] = "return PreviousPage()";
        DropDownList ddl = new DropDownList();
        ddl.ID = "DropDownList1";
        for (int i = 1; i $$<=$$ 12; i++)
        {
                ddl.Items.Add(i.ToString());
        }
        ddl.Attributes["onchange"] = "return IndexChanged()";
        HtmlButton nextButton = new HtmlButton();
        nextButton.InnerText = "Next";
        nextButton.Attributes["onclick"] = "return NextPage()";
        container.Controls.Add(prevButton);
        container.Controls.Add(ddl);
        container.Controls.Add(nextButton);
        }
        #endregion
}

If Not Page.IsPostBack Then
    '動作を追加します
    Me.WebDataGrid1.Behaviors.CreateBehavior(Of Paging)()
    'PageIndexChanged イベントを処理します
    Me.WebDataGrid1.Behaviors.Paging.PagingClientEvents.PageIndexChanged = "WebDataGrid1_PageIndexChanged"
End If
Me.WebDataGrid1.Behaviors.Paging.PagerTemplate = New CustomPagerTemplate()

if (!Page.IsPostBack)
{
        //動作を追加します
        this.WebDataGrid1.Behaviors.CreateBehavior<Paging>();
        //PageIndexChanged イベントを処理します
        this.WebDataGrid1.Behaviors.Paging.PagingClientEvents.PageIndexChanged = "WebDataGrid1_PageIndexChanged";
}
this.WebDataGrid1.Behaviors.Paging.PagerTemplate = new CustomPagerTemplate();

function IndexChanged() {
        var dropdownlist = document.getElementById("WebDataGrid1_ctl00_DropDownList1");
        var grid = $find("WebDataGrid1");
        var newValue = dropdownlist.selectedIndex;
        grid.get_behaviors().get_paging().set_pageIndex(newValue);
}

function PreviousPage() {
        var grid = $find("WebDataGrid1");
        var dropdownlist = document.getElementById("WebDataGrid1_ctl00_DropDownList1");
        if( grid.get_behaviors().get_paging().get_pageIndex() > 0 ) {
                grid.get_behaviors().get_paging().set_pageIndex(grid.get_behaviors().get_paging().get_pageIndex() - 1);
        }
}

function NextPage() {
        var grid = $find("WebDataGrid1");
        var dropdownlist = document.getElementById("WebDataGrid1_ctl00_DropDownList1");
        if(grid.get_behaviors().get_paging().get_pageIndex() < grid.get_behaviors().get_paging().get_pageCount() - 1) {
                grid.get_behaviors().get_paging().set_pageIndex(grid.get_behaviors().get_paging().get_pageIndex() + 1);
        }
}

function WebDataGrid1_PageIndexChanged() {
    var grid = $find("WebDataGrid1");
    var dropdownlist = document.getElementById("WebDataGrid1_ctl00_DropDownList1");
    dropdownlist.options[grid.get_behaviors().get_paging().get_pageIndex()].selected = true;
}