ComboBox and TextSearch = Exception

[Michele]

Hello,
I got this strange behavior siunce Q2 but since it happens only on my dev machine and not in production I was not too much intrested in the cause... the problem is I've got a RadComboBox with TextSearch enabled.... I've got almost 13000 items in the combobox and when I start typing I got this exception

Microsoft JScript runtime error: Sys.InvalidOperationException: ManagedRuntimeError error #4004 in control 'Xaml1': System.NullReferenceException: Object reference not set to an instance of an object. <br>&nbsp;&nbsp; at System.Windows.DependencyPropertyChangedWeakListener.Disconnect() <br>&nbsp;&nbsp; at System.Windows.DependencyPropertyChangedWeakListener.SourcePropertyChanged(DependencyObject c, DependencyProperty dp) <br>&nbsp;&nbsp; at System.Windows.DPChangedEventHandler.Invoke(DependencyObject sender, DependencyProperty dp) <br>&nbsp;&nbsp; at System.Windows.DependencyObject.OnPropertyChanged(DependencyProperty dp) <br>&nbsp;&nbsp; at System.Windows.FrameworkElement.OnPropertyChanged(DependencyProperty dp) <br>&nbsp;&nbsp; at System.Windows.DependencyObject.SetValueInternal(DependencyProperty dp, Object value, Boolean allowReadOnlySet, Boolean isSetByStyle, Boolean isSetByBuiltInStyle, PropertyInvalidationReason reason) <br>&nbsp;&nbsp; at System.Windows.DependencyObject.SetValueInternal(DependencyProperty dp, Object value) <br>&nbsp;&nbsp; at System.Windows.DependencyObject.SetValue(DependencyProperty dp, Object value) <br>&nbsp;&nbsp; at Telerik.Windows.Controls.RadComboBox.set_Text(String value) <br>&nbsp;&nbsp; at Telerik.Windows.Controls.RadComboBox.TextUpdated(String newText, Boolean textBoxUpdated) <br>&nbsp;&nbsp; at Telerik.Windows.Controls.RadComboBox.OnEditableTextBoxTextChanged(Object sender, TextChangedEventArgs e) <br>&nbsp;&nbsp; at System.Windows.CoreInvokeHandler.InvokeEventHandler(Int32 typeIndex, Delegate handlerDelegate, Object sender, Object args) <br>&nbsp;&nbsp; at MS.Internal.JoltHelper.FireEvent(IntPtr unmanagedObj, IntPtr unmanagedObjArgs, Int32 argsTypeIndex, String eventName)

Here's my code :

cs file :

 

public partial class Inserimento : UserControl, IParentHoldCliente, IDisposable, IParentHoldFondo <br>&nbsp;&nbsp;&nbsp; { <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; #region Variables <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; private IFWebLight.DO.IFMondoAParte.MondoAParteClient clientMAP; <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; private IFWebLight.DO.IFPosizione.PosizioneClient clientPOS; <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; private Cliente m_Cliente; <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; private ClientDataSource clientDataSource; <br>&nbsp;<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; private double m_qty = 0; <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; private double m_nav = 0; <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; private double m_ctv = 0; <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; private DateTime m_OrderTime; <br>[...] <br>&nbsp;<br>&nbsp;&nbsp;&nbsp;&nbsp; private void LoadClientList() <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; { <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; if (App.m_ListaCliente == null) <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; { <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; clientPOS.GetListaClientiAsync(App.UserName); <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; } <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; else <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; { <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; cbNDG.IsEnabled = true; <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; clientDataSource = new ClientDataSource(App.m_ListaCliente, "D"); <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; cbNDG.DataContext = clientDataSource; <br>&nbsp;<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; clientMAP.GetModalitaRicezioneOrdiniAsync(App.UserName); <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; } <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; }

 
and XAML :

&nbsp; &lt;StackPanel Grid.Row="0" Grid.Column="0" Grid.ColumnSpan="2" Orientation="Horizontal" Margin="0,5,0,0" &gt; <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &lt;TextBlock Text="Dossier" TextAlignment="Left" Margin="5,0,0,0" VerticalAlignment="Center" HorizontalAlignment="Left" Width="100" Height="16"/&gt; <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &lt;telerikInput:RadComboBox GotFocus="cbNDG_GotFocus"&nbsp; Margin="10,0,0,0" x:Name="cbNDG" Height="16" Width="120" IsTextSearchEnabled="False" IsEditable="True" IsEnabled="False" KeyDown="cbNDG_KeyDown" <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Text="{Binding Text, Mode=TwoWay}" SelectionChanged="cbNDG_SelectionChanged"&nbsp; Tag="NDG" ItemsSource="{Binding FoundClient}" DisplayMemberPath="D"/&gt; <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &lt;TextBox x:Name="tbIntestatario" HorizontalAlignment="Right" TextWrapping="Wrap" Width="190" Background="LightGray" IsReadOnly="True" /&gt; <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &lt;Button x:Name="btnSearchCliente" Margin="5,0,0,0" Content="Search" HorizontalAlignment="Right" Width="40" Height="20" FontSize="10" Click="btnSearchCliente_Click" /&gt; <br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &lt;/StackPanel&gt;

Hope it helps...
Thanks

[Valeri Hristov]

Hi Paolo,

I guess you already enabled the virtualization of RadComboBox, since it is not very useful with 1000+ items and no virtualization. It is possible that the older versions contain bugs related to this scenario so I would recommend trying the latest internal build of the control, available here:
http://www.telerik.com/account/downloads/internal-builds.aspx

If the problem persists, I would like to kindly ask you for a simple application that could be used to observe the problem.

All the best,
Valeri Hristov
the Telerik team

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