Monika Dyrda

WPF Binding ItemsSource to Enum

I have found a very neat and simple way of binding an ItemControl to enum values. The trick is to use an ObjectDataProvider class which enables the creation of a XAML object available as a binding source.

To show an example first of all I need an enum:

public enum SampleEnum
{
     Dog,
     Cat,
     Scrat,
     Hefalump
}

To make it available for binding I will define it as a resource with an x:Key.

<Window x:Class="WpfApplication1.Window1"
 xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
 xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
 xmlns:System="clr-namespace:System;assembly=mscorlib"
 xmlns:local="clr-namespace:WpfApplication1"
 Title="Bind to Enum" Height="250" Width="250">
<Window.Resources>
     <ObjectDataProvider x:Key="dataFromEnum"
       MethodName="GetValues" ObjectType="{x:Type System:Enum}">
          <ObjectDataProvider.MethodParameters>
               <x:Type TypeName="local:SampleEnum"/>
          </ObjectDataProvider.MethodParameters>
     </ObjectDataProvider>
</Window.Resources>
</Window>

This code creates the ObjectDataProvider in the window with ObjectType property set to Enum and MethodName property set to GetValues method of the Enum class. Then a specific enum (SampleEnum) is set to MethodParameter attribute.

Having this resource we can bind it as an ItemsSource to a ListView and Combobox (or any other ItemsControl) by setting items source:

ItemsSource="{Binding Source={StaticResource dataFromEnum}}"

The XAML for the window is as follows:

<Window x:Class="WpfApplication1.Window1"
 xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
 xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
 xmlns:System="clr-namespace:System;assembly=mscorlib"
 xmlns:local="clr-namespace:WpfApplication1"
 Title="Bind to Enum" Height="250" Width="250">
<Window.Resources>
     <ObjectDataProvider x:Key="dataFromEnum"
       MethodName="GetValues" ObjectType="{x:Type System:Enum}">
          <ObjectDataProvider.MethodParameters>
               <x:Type TypeName="local:SampleEnum"/>
          </ObjectDataProvider.MethodParameters>
     </ObjectDataProvider>
</Window.Resources>
<Grid>
     <ListView ItemsSource="{Binding Source={StaticResource dataFromEnum}}"
      Margin="10,10,10,0" Height="80" VerticalAlignment="Top" />
     <ComboBox ItemsSource="{Binding Source={StaticResource dataFromEnum}}"
      Margin="10,0,10,80" Height="25" VerticalAlignment="Bottom" />
</Grid>
</Window>

The code behind for window is:

using System.Windows;
namespace WpfApplication1
{
     public partial class Window1 : Window
     {
          public Window1()
          {
               InitializeComponent();
          }
     }
     public enum SampleEnum
     {
          Dog,
          Cat,
          Scrat,
          Hefalump
     }
}

And the result:

Happy Binding! ;-)

Monika

WPF Control content with curly braces

For some people it is obvious but for me it was quite a discovery when I’ve found out how to insert curly braces into a Text or Content of a control. Surely you can’t simply write:

<Button Content="{Curly braces here}"/>

because in XAML, braces identify markup extension syntax and you would get a compiler error ( The tag 'Curly' does not exist in XML namespace…).

Instead you should prefix the content with another pair of braces. Here is an example:

<StackPanel>
            <Button Content="{}{Curly braces here}" 
                    Margin="10" Width="120" />
            <TextBox Text="{}{Curly braces there}" 
             Margin="10" Width="120"/>
            <Label Content="{}{I can put them everywhere! ;-)}" 
             Margin="10" Width="180"/>
</StackPanel>

And the result looks like that:

I recommend reading WPF Recipes in C# 2008: A Problem-Solution Approach which has tons of this kind of useful recipes.

Monika