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UIElement.Focusable Property

  • Reference

Definition

Namespace:
System.Windows
Assembly:
PresentationCore.dll

Gets or sets a value that indicates whether the element can receive focus. This is a dependency property.

public:
 property bool Focusable { bool get(); void set(bool value); };
public bool Focusable { get; set; }
member this.Focusable : bool with get, set
Public Property Focusable As Boolean

Property Value

Boolean

true if the element is focusable; otherwise false. The default is false.

Implements

Focusable

Examples

The following example code illustrates a control template for a particular custom control, which sets Focusable false on one of the elements within the template.

<Window.Resources>
  <Style x:Key="TextBoxNoScrollViewer" TargetType="{x:Type TextBoxBase}">
    <Setter Property="Template">
      <Setter.Value>
        <ControlTemplate TargetType="{x:Type TextBoxBase}">
          <Border 
            CornerRadius="2" 
            Background="{TemplateBinding Background}" 
            BorderThickness="{TemplateBinding BorderThickness}" 
            BorderBrush="{TemplateBinding BorderBrush}"  
          >
            <!-- 
            The control template for a TextBox or RichTextBox must
            include an element tagged as the content host.  An element is 
            tagged as the content host element when it has the special name
            PART_ContentHost.  The content host element must be a ScrollViewer,
            or an element that derives from Decorator.  
            -->
            <AdornerDecorator 
              x:Name="PART_ContentHost"
              Focusable="False" 
            />
          </Border>
        </ControlTemplate>
      </Setter.Value>
    </Setter>
  </Style>
</Window.Resources>

Remarks

Only the focused element receives keyboard input.

Focusable is the Microsoft .NET property accessor for what is in reality a dependency property. This particular dependency property quite frequently has its apparent "default" value set differently in derived element classes, particularly in controls. This commonly occurs in one of two ways:

  • The dependency property is inherited by a particular derived class, but that derived class overrides the metadata of the dependency property and changes the property default value.

  • A style or template is applied to an element, which sets that dependency property value differently.

For example, the apparent "default" of Focusable for a Button control will be true, even though Button inherits Focusable as a common language runtime (CLR) property directly from UIElement. This is because the applied metadata value for the Focusable dependency property was overridden within the static constructor of the Control base class, which is situated between Button and UIElement in the class hierarchy.

When inherited by Control or its derived classes, Control redefines the default value of this property to be true.

When inherited by Label (which is a Control derived class), the default value is again redefined to be false.

Dependency Property Information
Identifier field FocusableProperty
Metadata properties set to true None

Notes to Inheritors

When deriving from UIElement directly (as opposed to from Control), consider whether you wish your element to be focusable, because by default the element will not be focusable. If you wish your element to be focusable, override the metadata for this property within your type's static constructor as follows:

FocusableProperty.OverrideMetadata(typeof(myElement), new UIPropertyMetadata(true));

FocusableProperty.OverrideMetadata(GetType(myElement), New UIPropertyMetadata(True))

where myElement should be the class name of the type that you are overriding the metadata value on.

Applies to

See also