Populate RadComboBoxItemsRequestedEventArgs Text property

[Eugen]

Hi,

I have a RadCombobox on an aspx page that I'm trying to populate with one item at OnLoad using 

RadComboBoxItem newItem = getItem(id);
RadCombo1.Items.Add(newItem);
RadCombo1.SelectedValue = Request.QueryString["cid"];
RadCombo1.Text = newItem.Text;

After page finishes loading, while invoking RadCombo1_ItemsRequested(object sender, RadComboBoxItemsRequestedEventArgs e), e has empty Text and loads data as if the box was empty.

Control on page:

<telerik:RadComboBox ID="RadCombo1" runat="server" 
                                        Width="300" MaxHeight="350" AllowCustomText="true" 
                                        MarkFirstMatch="true" 
                                        OnClientSelectedIndexChanged="OnClientSelectedIndexChanged"
                                        OnSelectedIndexChanged="RadCombo1_SelectedIndexChanged"
                                        EnableLoadOnDemand="true" EnableVirtualScrolling="true"
                                        OnItemsRequested="RadCombo1_ItemsRequested"
                                        ShowMoreResultsBox="true" Filter="Contains">
                                    </telerik:RadComboBox>

 

How can I set e.Text to my selectedItem.Text or invoke manually RadCombo1_ItemsRequested ?

[Ivan Danchev]

Hello,

In a Load on Demand scenario a better approach of adding new ComboBox items would be to use the ItemsRequested event handler and add the items in it, as demonstrated in the sample project attached to this reply.

e.Text in the context of the ItemsRequested event holds the text in the RadComboBox' input field but in order for that event to fire the user must type text into the input field or click on the drop-down toggle image when the list is empty. A third way to trigger the event is by calling the RadComboBox requestItems() client-side method. You can find more information about this method in the RadComboBox Object documentation article.

Regards,
Ivan Danchev
Telerik

[Eugen]

Hi,

Thanks for response. RequestItems did the job with one issue: after using it, load on demand will get me only the first page of items ( scrolling down the list will not continue to fire ItemsRequested on server side). Any ideas why?

[Ivan Danchev]

Hello,

Is the configuration of the ComboBox any different from the one in your first post and which event handler do you call the requestItems() method in?

Regards,
Ivan Danchev
Telerik

[Eugen]

Configuration is the same.

Initially I tried to use requestItems on js pageLoad().

I also tried to do that on a checkbox client event but that failed as this call is asynch and I needed the item right away.

Just to clear thing out:

I have RadComboBox with LoadOnDemand. On c# Page_Load I want to populate the Combo with one item based on QueryString and then Combo should work normally, no duplicates in the list of items, no blocking of items loading process.

Thank you

[Ivan Danchev]

Hello,

Did you try adding the item as suggested in the ItemsRequested handler and not in Page_Load? At my side this works correctly and if the ComboBox ItemsPerRequest property is not set the item will be added at the end of the Items collection without any repetition. Setting the ItemsPerRequest will create repetition as the item will be added after each set of requested items.

Regards,
Ivan Danchev
Telerik