Introduction

Many would have come across a scenario where-in you need to disable some of the items in comboBox based on business needs or project requirements. This tip will help you to do the same.

Using the Code

Step 1: Create Combobox in XAML and bind ItemSource of ComboBox

< Window x:Class =" ComboboxDisable.WPFComboboxWindow" xmlns =" http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x =" http://schemas.microsoft.com/winfx/2006/xaml" Title =" ComboboxItemDisable" Height =" 165" Width =" 332" xmlns:local =" clr-namespace:ComboboxDisable" > < Grid Height =" 130" Width =" 316" > < ComboBox Height =" 23" HorizontalAlignment =" Left" Margin =" 78,12,0,0" Name =" comboBox1" VerticalAlignment =" Top" Width =" 120" ItemsSource =" {Binding Items}" Background =" Bisque" Foreground =" Black" SelectedIndex =" 0" > < /ComboBox > < /Grid > < /Window >

Step 2: Create Class for Binding Itemsource with List<String> collections

public class ExampleClass // Field for storing collection private List<String> items; // Property for Storing Collections public List<String> Items get { return items; } set {items = value ;} /// < summary > /// Constructor /// < /summary > public ExampleClass() items = new List<String>(); items.Add( " CollectionItem1" ); items.Add( " CollectionItem2" ); items.Add( " CollectionItem3" ); items.Add( " CollectionItem4" ); items.Add( " CollectionItem5" );

Step 3: Create Converter Class for Disabling Items in ComboBox

Below Converter will disable 2 ^nd and 3 ^rd Items from ComboBox [You can have your own custom logic for which condition the combobox item should be disabled].

namespace ComboboxDisable // Converter for disabling ComboboxItem class ComboboxDisableConverter : IValueConverter public object Convert( object value , Type targetType, object parameter, System.Globalization.CultureInfo culture) if ( value == null ) return value ; // You can add your custom logic here to disable combobox item if ( value == " CollectionItem2" || value == " CollectionItem3" ) return true ; return false ; public object ConvertBack( object value , Type targetType, object parameter, System.Globalization.CultureInfo culture) throw new NotImplementedException();

Step 4: Now modify your XAML file by specifying the ItemContainerStyle for ComboBox and including Converter

<!-- Resource for Combobox to --> < ComboBox.Resources > < local:ComboboxDisableConverter x:Key =" itemDisableconverter" / > < /ComboBox.Resources > <!-- ItemContainer Style for disabling Combobox Item --> < ComboBox.ItemContainerStyle > < Style TargetType =" ComboBoxItem" > < Style.Triggers > < DataTrigger Binding =" {Binding Path=Content, RelativeSource={RelativeSource Self}, Converter={StaticResource itemDisableconverter}}" Value =" true" > < Setter Property =" IsEnabled" Value =" False" / > < /DataTrigger > < /Style.Triggers > < /Style > < /ComboBox.ItemContainerStyle >

By including the above set of blocks in your XAML, your final XAML will look like the below one:

< Window x:Class =" ComboboxDisable.WPFComboboxWindow" xmlns =" http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x =" http://schemas.microsoft.com/winfx/2006/xaml" Title =" ComboboxItemDisable" Height =" 165" Width =" 332" xmlns:local =" clr-namespace:ComboboxDisable" > < Grid Height =" 130" Width =" 316" > < ComboBox Height =" 23" HorizontalAlignment =" Left" Margin =" 78,12,0,0" Name =" comboBox1" VerticalAlignment =" Top" Width =" 120" ItemsSource =" {Binding Items}" Background =" Bisque" Foreground =" Black" SelectedIndex =" 0" > <!-- Resource for Combobox to --> < ComboBox.Resources > < local:ComboboxDisableConverter x:Key =" itemDisableconverter" / > < /ComboBox.Resources > <!-- ItemContainer Style for disabling Combobox Item --> < ComboBox.ItemContainerStyle > < Style TargetType =" ComboBoxItem" > < Style.Triggers > < DataTrigger Binding =" {Binding Path=Content, RelativeSource={RelativeSource Self}, Converter={StaticResource itemDisableconverter}}" Value =" true" > < Setter Property =" IsEnabled" Value =" False" / > < /DataTrigger > < /Style.Triggers > < /Style > < /ComboBox.ItemContainerStyle > < /ComboBox > < /Grid > < /Window >

Execute the project and open the comboBox . You will see the 2 ^nd and 3 ^rd items are disabled and user can't select them.

You also can download the same from the attachment at the top of this tip.

Hello,
Could you please guide me in disallowing selection of disabled combobox item in below code?
< DataTemplate x:Key =" DataTemplateTopLevelCombobox2" > < Border Width =" 100" > < ComboBox Text =" Custom" Height =" 21.96" ItemsSource =" {Binding DataContext.Models, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Window}}}" IsEnabled =" {Binding DataContext.EnableCombo, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Window}}}" < /Border > < /DataTemplate >
Full problem is posted @ http://stackoverflow.com/questions/20889963/disallow-block-selection-of-disabled-combobox-item-in-wpf

Cheers,
Vishal

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