Performance problem with 5000 combobox items

[Danny Scheelings]

Hello,

I am using the RadComboBox as an autocomplete control, so I set the following properties:
IsEditable="True" CanAutocompleteSelectItems="True" OpenDropDownOnFocus="False" CanKeyboardNavigationSelectItems="True"

The combobox is filled with 5000 cities. When I enter one character, the autocomplete functionality is working fine. But when I want to open the combobox by clicking the DropDownIcon the webbrowser crashes after some time. The CPU is also peaking at 100%. So there is really a performance problem.

I have 2 questions:
1. Is there a better way to handle these amount of combobox items?
2. Can the DropDownIcon be hidden so the combobox cannot be opened anymore and will only be used as an autocomplete textbox?

Thanks,
Danny

[Valeri Hristov]

Hello Danny,

You need to enable the virtualization of RadComboBox:
http://www.telerik.com/help/silverlight/radcombobox-howto-virtualization.html

You cannot hide the dropdown button of RadComboBox with a property setting. You will have to edit the control template.

Greetings,
Valeri Hristov
the Telerik team

[Danny Scheelings]

Yes, it works great !!

Thanks!

[Ari]

Hi, using the VirtualizingStackPanel causes the filtering not to work (IsFilteringEnabled = true is ignored).
Any solution?

Thanks,
Ari

[Konstantina]

Hi Ari,

Thank you for contacting us.

Unfortunately, filtering and virtualization are not supported by the RadComboBox together. We will consider addressing this issue in one of our future releases.
Sorry if that causes you any inconvenience.

If you have any other questions about our controls let us know.

Sincerely yours,
Konstantina
the Telerik team

[JJ Loubser]

mine is like this, the source is been set with code behind, and it works, but I cannot select anything, when I select A value it go back to blank, why?
we want to text in values and the combobox must get it then click with mouse to select it, but then it turn to blank
allso we want to see what we text in like when  IsEditable="True" , but when it is true then you can text in stuff and values we do not want the user to type in, the user must only type in stuff in the list, How can we solve this?

                                   <telerik:RadComboBox
                                        x:Name="EditCompleteBox"
                   Background="{StaticResource BrushBackgroundAllControls}"
                   Text="" 
                           DisplayMemberPath="Value" 
                                        <telerik:RadComboBox
                                        x:Name="EditCompleteBox"
                   Background="{StaticResource BrushBackgroundAllControls}"
                   Text="" 
                           DisplayMemberPath="Value" 
                                        IsEditable="False"
                                        telerik:TextSearch.TextPath="Value"
                                        TextSearchMode="StartsWith"
                                        CanKeyboardNavigationSelectItems="True"
                                        IsMouseWheelEnabled="True"
                                        SelectionChanged="EditCompleteBox_SelectionChanged"
                                        KeyUp="EditCompleteBox_KeyUp"
                                        Width="168" Height="33"
                                        Loaded="EditCompleteBox_Loaded"
                                        StaysOpenOnEdit="True"
                                        OpenDropDownOnFocus="True"
                                        VirtualizingStackPanel.VirtualizationMode="Recycling"
                                        >
                                       

[JJ Loubser]

working fine now answer:

 <telerik:RadComboBox
                                                                x:Name="EditCompleteBox"
                                           Text="{Binding Model.NearestTown, Mode=TwoWay}"
                                                                Tag="{Binding Model.PostalCodeID, Mode=TwoWay}"
                                                   DisplayMemberPath="Value" 
                                                                IsEditable="False"
                                                                telerik:TextSearch.TextPath="Value"
                                                                TextSearchMode="StartsWith"
                                                                CanKeyboardNavigationSelectItems="True"
                                                                IsMouseWheelEnabled="True"
                                                                SelectionChanged="EditCompleteBox_SelectionChanged"
                                                                ItemsSource="{Binding Model.TownList, Mode=TwoWay}"
                                                                Width="250" Height="30"
                                                                Loaded="EditCompleteBox_Loaded"
                                                                StaysOpenOnEdit="True"
                                                                OpenDropDownOnFocus="True"
                                                                VirtualizingStackPanel.VirtualizationMode="Recycling"
                                                                Background="Orange"
                                                                >


                                                            <telerik:RadComboBox.ItemsPanel>
                                                                <ItemsPanelTemplate>
                                                                    <VirtualizingStackPanel/>


                                                                </ItemsPanelTemplate>
                                                            </telerik:RadComboBox.ItemsPanel>


                                                        </telerik:RadComboBox>