<ComboBox Name="cbDesignation" IsEditable="True" TextSearch.TextPath="DesignationName"
StaysOpenOnEdit="True" ItemsSource="{Binding Path=DesignationCollection,Mode=TwoWay}"
SelectedItem="{Binding Path=SelectedDesignation,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged,ValidatesOnDataErrors=True}"
VerticalAlignment="Center">
<ComboBox.ItemsPanel>
<ItemsPanelTemplate>
<VirtualizingStackPanel/>
</ItemsPanelTemplate>
</ComboBox.ItemsPanel>
<ComboBox.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding Path=DesignationName}" VerticalAlignment="Center" Grid.Column="1" Margin="5,0,0,0"/>
</DataTemplate>
</ComboBox.ItemTemplate>
</ComboBox>
If it is editable then it search but only one item I want that whrn user enter start of alphabet then it will show all the list regardin this alphabet
How about an AutoComplete TextBox instead? It also uses suggestions and does all the filtering for you. You can find one here:
http://wpfactb.codeplex.com/
(more info here: http://blogs.windowsclient.net/dragonz/archive/2010/02/23/autocomplete-textbox-control-for-wpf.aspx)