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ListView, Paging and SortOrder

14 Answers 283 Views

ListView

This is a migrated thread and some comments may be shown as answers.

14 Answers, 1 is accepted

answered on 04 Mar 2011, 07:53 PM

Hi I am experiencing the same thing.

I have a RadListView with a RadDataPager and when I set AllowPaging to false and sort the data bound to RadListView manually it works as expected. But when I set AllowPaging to true although the data that I bind to RadLisView is in correct order in ItemDataBound I get the DataItems as if the data is not sorted at all.

protected void news_NeedDataSource(object sender, Telerik.Web.UI.RadListViewNeedDataSourceEventArgs e)

{

NewsManager manager = new NewsManager();

foreach (SortFieldView view in SortByList)

{

if (view.SortDirection != SortDirection.None)

{

manager.AddSortField(view.SortField, view.SortDirection);

}

var newsList = manager.GetNews();

List<NewsItem> list = newsList.ToList();

news.DataSource = list;

}

protected void news_ItemDataBound(object sender, Telerik.Web.UI.RadListViewItemEventArgs e)

{

if (e.Item.ItemType == Telerik.Web.UI.RadListViewItemType.DataItem ||

e.Item.ItemType == Telerik.Web.UI.RadListViewItemType.AlternatingItem)

{

RadListViewDataItem viewItem = (RadListViewDataItem)e.Item;

NewsItemControl newsItemControl = (NewsItemControl)e.Item.FindControl("newsItem");

NewsItem news = (NewsItem)viewItem.DataItem;

newsItemControl.Update(news);

}

<telerik:RadListView ID="news" runat="server"

onitemdatabound="news_ItemDataBound"

onneeddatasource="news_NeedDataSource" AllowPaging="true">

<ItemTemplate>

<uc2:NewsItemControl ID="newsItem" runat="server" />

</ItemTemplate>

</telerik:RadListView>

<telerik:RadDataPager ID="pager" runat="server"

PagedControlID="news" PageSize="4" EnableEmbeddedSkins="false">

<Fields>

<telerik:RadDataPagerTemplatePageField HorizontalPosition="RightFloat" >

<PagerTemplate>

<asp:LinkButton Visible="<%# Container.Owner.StartRowIndex == 0 ? false : true %>"

ID="btnPrev" runat="server" CommandName="Page" CommandArgument="Prev">< Newer</asp:LinkButton>

<asp:LinkButton

Visible="<%# Container.Owner.TotalRowCount < Container.Owner.StartRowIndex+Container.Owner.PageSize ? false : true %>"

ID="btnNext" runat="server" CommandName="Page" CommandArgument="Next">Older ></asp:LinkButton>

</PagerTemplate>

</telerik:RadDataPagerTemplatePageField>

<telerik:RadDataPagerTemplatePageField HorizontalPosition="RightFloat" >

<PagerTemplate>

<asp:Label runat="server" ID="CurrentPageLabel" Text="<%# Container.Owner.StartRowIndex+1%>" />

to

<asp:Label runat="server" ID="TotalPagesLabel" Text="<%# Container.Owner.TotalRowCount < Container.Owner.StartRowIndex+Container.Owner.PageSize ?

Container.Owner.TotalRowCount : Container.Owner.StartRowIndex+Container.Owner.PageSize %>" />

of

<asp:Label runat="server" ID="TotalItemsLabel" Text="<%# Container.Owner.TotalRowCount%>" />

<br />

</PagerTemplate>

</telerik:RadDataPagerTemplatePageField>

</Fields>

</telerik:RadDataPager>

Thank you...

answered on 08 Mar 2011, 05:15 PM

Hi Eric,

I tested the project provided in the support thread and here are my findings:

After further debugging it appeared the issue is due to a limitation in the Entity Framework. In order allow paging, e.g. to be able to call the Skip() and Take() methods, the list of records should be sorted. Therefore the RadListView is sorting the data source is sorted by the first data field. However I have forwarded the issue to our developers and they will change the listview behavior so sorting will work with page if the sorting is performed through the listview API, i.e. is sort expressions are added to it. In this case the sorting will be still performed at database level but the listview will pass the sort expressions to it for you.

Regards,
Iana
the Telerik team

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