RadListViewDataItem Retrieval in UI for ASP.NET AJAX ListView

robertw102

265 posts

Member since:
Jul 2007

Posted 19 Nov 2009 Link to this post

I'm using the RadListView in my project which is setup like so:

                    <telerik:RadListView ID="lvCalendars" runat="server" AllowPaging="True" DataKeyNames="Listing_ID"         
                        DataSourceID="dsListing" OnItemDataBound="lvCalendars_ItemDataBound">         
                        <LayoutTemplate>         
                            <telerik:RadDataPager ID="dpTopPager" runat="server" PagedControlID="lvCalendars"         
                                PageSize="7" Skin="Office2007">         
                                <Fields>         
                                    <telerik:RadDataPagerButtonField FieldType="Numeric" PageButtonCount="10" />         
                                </Fields>         
                            </telerik:RadDataPager>         
                            <table cellpadding="0" cellspacing="0" width="100%" class="bgStandardMedium">         
                                <tr id="itemPlaceholder" runat="server">         
                                </tr>         
                            </table>         
                            <telerik:RadDataPager ID="dpBottomPager" runat="server" PagedControlID="lvCalendars"         
                                PageSize="7" Skin="Office2007">         
                                <Fields>         
                                    <telerik:RadDataPagerButtonField FieldType="Numeric" PageButtonCount="10" />         
                                </Fields>         
                            </telerik:RadDataPager>         
                        </LayoutTemplate>         
                        <ItemTemplate>         
                            <tr>         
                                <td class="bgStandardDark propertySection">         
                                    <asp:Image ID="imgProperty" runat="server" Width="130px" Height="90px" AlternateText='<%#Eval("Name") %>'         
                                        ToolTip='<%#Eval("Name") %>' />         
                                    <span class="propertyName">         
                                        <%#DataBinder.Eval(Container, "DataItem.Name").ToString() %>         
                                    </span>         
                                    <asp:HyperLink ID="lnkBookProperty" runat="server" CssClass="buttonStandard" Text="<span>Book Property</span>"         
                                        Width="170px"></asp:HyperLink>         
                                    <br />         
                                    <br />         
                                    <asp:LinkButton ID="lnkPrintCalendar" runat="server" CssClass="buttonStandard" Width="170px"         
                                        Text="<span>Print Reservation List</span>"></asp:LinkButton>         
                                </td>         
                                <td class="calendarSection">         
                                    <telerik:RadAjaxPanel ID="apBookingCalendar" runat="server" LoadingPanelID="LoadingPanel1">         
                                        <telerik:RadCalendar ID="calBooking" runat="server" MultiViewColumns="4" MultiViewRows="1"         
                                            EnableMultiSelect="false" ShowRowHeaders="False" ShowOtherMonthsDays="False"         
                                            AutoPostBack="True" CssClass="bookingCalendar" OnDefaultViewChanged="calBooking_DefaultViewChanged">         
                                            <CalendarTableStyle Width="175px" Height="196px" />         
                                        </telerik:RadCalendar>         
                                        <div class="button-row" style="text-align: center;">         
                                            <asp:LinkButton ID="lnkbtnViewFullYear" runat="server" CssClass="buttonStandard"         
                                                Text="<span>View Full Year</span>" Width="150px" />         
                                        </div>         
                                    </telerik:RadAjaxPanel>         
                                    </li>         
                                </td>         
                        </ItemTemplate>         
                    </telerik:RadListView>         

Now in my calendar's OnDefaultViewChanged event I attempt to retrieve the RadListViewDataItem it's contained in like so:

                    protected void calBooking_DefaultViewChanged(Object sender, Telerik.Web.UI.Calendar.DefaultViewChangedEventArgs e)         
                {         
                    try         
                    {         
                        // get calendar         
                        RadCalendar calBooking = (RadCalendar)sender;         
                        // get RadListViewDataItem         
                        RadListViewDataItem dtItem = (RadListViewDataItem)calBooking.Parent.Parent;         
                     
                        // hold Sub Listing         
                        SubListing subListing = new SubListing();         
                     
                        // hold Listing         
                        Listing listing;         
                     
                        // check if data item is a listing         
                        if (dtItem.DataItem is Listing)         
                        {         
                            // get listing         
                            listing = (Listing)dtItem.DataItem;         
                        }         
                        else         
                        {         
                            // get sub listing         
                            subListing = (SubListing)dtItem.DataItem;         
                            // get listing         
                            listing = subListing.Listing;         
                        }         
                     
                        //...calendar setup code follows        
                     
                    }         
                    catch (Exception ex)         
                    {         
                    }         
                }         

Now apparently DataItem does not exist, I get a null value. I was able to retrieve the DataItem object in the ItemDataBound event of the RadListView control but not in the calendar event.

Is there a reason for this or is it some bug in the RadListView control?

I am using the latest version of the controls 3.1105 (.NET 3.5).

Rosen

Admin

3253 posts

Posted 20 Nov 2009 Link to this post

Hi,

As you may know when using DataBoundControls, Item's DataItem property is only populated when control is created from the accosted datasource and not when the control is recreated from its ViewState. Therefore if you want to use some part of the object associated with an Item of ListView control, on an event which will not cause the control to be repopulated, you should use some other approach get the object. For example you can use DataKeyNames. This way you may retrieve the full object by its key or use the value directly if it is sufficient for the scenario in question.

Kind regards,
Rosen
the Telerik team

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cute gal

5 posts

Member since:
Mar 2010

Posted 26 Mar 2010 Link to this post

hi.. i want to print contents populated within radlistview
i wonder to get data and activate printer settings on the clink event of linkbutton..

    
             <asp:Panel ID="ListViewPanel1" runat="server"> 
        
                                <telerik:RadListView ID="RadListView1" runat="server" DataKeyNames="PrivacyId" DataSourceID="source1" 
        
                                    ItemPlaceholderID="ListViewContainer" RegisterWithScriptManager="true" allowsorting="true" 
        
                                    AllowPaging="True" Font-Names="Arial"> 
        
                                    <LayoutTemplate> 
        
                                        <asp:PlaceHolder ID="ListViewContainer" runat="server" /> 
        
                                    </LayoutTemplate> 
        
                                    <ItemTemplate> 
        
                                        <table> 
        
                                            <tr> 
        
                                                <td> 
        
                                                    &nbsp; 
        
                                                </td> 
        
                                            </tr> 
        
                                            <tr> 
        
                                                <td> 
        
                                                    <%#Eval("Heading")%> 
        
                                                </td> 
        
                                            </tr> 
        
                                            <tr> 
        
                                                <td> 
        
                                                    &nbsp; 
        
                                                </td> 
        
                                            </tr> 
        
                                            <tr> 
        
                                                <td> 
        
                                                    <%#Eval("Description")%> 
        
                                                </td> 
        
                                            </tr> 
        
                                        </table> 
        
                                    </ItemTemplate> 
        
                                </telerik:RadListView> 
        
                            </asp:Panel> 
        
            <asp:SqlDataSource ID="source1" runat="server" ConnectionString="<%$ ConnectionStrings:helpConnectionString %>" 
        
                                SelectCommand="SELECT * FROM [Privacy]"></asp:SqlDataSource> 
        
            <asp:LinkButton ID="lnkPrint" runat="server" >Print this Page</asp:LinkButton>

Rosen

Admin

3253 posts

Posted 29 Mar 2010 Link to this post

Hi,

There is no such functionality built into the RadListView. However you may look at this code library which demonstrates how to achieve similar thing with RadGrid and adapt the code to fit your case.

All the best,
Rosen
the Telerik team

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Kiran

57 posts

Member since:
Oct 2018

Posted 04 Nov 2019 in reply to Rosen Link to this post

Hi Rosen,

Can you please post an example on how to retrieve datakeyvalue on the raddatapager change? I have radlistview with raddatapager. One item per page. On clicking on the next button of the raddatapager I want to grab the value (datakeyvalue).

Thank you.

Rumen

Admin

14419 posts

Posted 07 Nov 2019 Link to this post

Hi Kiran,

You can attach to the OnCommand server event of the RadDataPager to check for the PageCommandName and extract the value of the ListBoxDataItem like this:

var dataKeyValue = (RadListView1.Items[0] as RadListViewDataItem).GetDataKeyValue("CustomerID").ToString();

Here is an example based on the RadListView overview demo:

ASPX

<telerik:RadDataPager RenderMode="Lightweight" ID="RadDataPager1" runat="server" PagedControlID="RadListView1" OnCommand="RadDataPager1_Command"
    PageSize="2" CssClass="pagerStyle">
    <Fields>
        <telerik:RadDataPagerButtonField FieldType="FirstPrev"></telerik:RadDataPagerButtonField>
        <telerik:RadDataPagerButtonField FieldType="Numeric" PageButtonCount="4"></telerik:RadDataPagerButtonField>
        <telerik:RadDataPagerButtonField FieldType="NextLast"></telerik:RadDataPagerButtonField>
        <telerik:RadDataPagerPageSizeField PageSizeComboWidth="60" PageSizeText="Page size: "></telerik:RadDataPagerPageSizeField>
        <telerik:RadDataPagerGoToPageField CurrentPageText="Page: " TotalPageText="of" SubmitButtonText="Go"></telerik:RadDataPagerGoToPageField>
    </Fields>
</telerik:RadDataPager>

Codebehind:

        protected void RadDataPager1_Command(object sender, RadDataPagerCommandEventArgs e)
        {
            if (e.CommandName == RadDataPager.PageCommandName) {
                var dataKeyValue = (RadListView1.Items[0] as RadListViewDataItem).GetDataKeyValue("CustomerID").ToString();
            }
        }

Best Regards,
Rumen
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Kiran

57 posts

Member since:
Oct 2018

Posted 07 Nov 2019 in reply to Rumen Link to this post

Thank you so much Rumen.

Rumen

Admin

14419 posts

Posted 07 Nov 2019 Link to this post

Great! Keep up the good work.

Regards,
Rumen
Progress Telerik

Get quickly onboarded and successful with your Telerik and/or Kendo UI products with the Virtual Classroom free technical training, available to all active customers. Learn More.