Breyta

Deila með

FrameworkElement.Parent Property

  • Reference

Definition

Namespace:
System.Windows
Assembly:
PresentationFramework.dll

Gets the logical parent element of this element.

public:
 property System::Windows::DependencyObject ^ Parent { System::Windows::DependencyObject ^ get(); };
public System.Windows.DependencyObject Parent { get; }
member this.Parent : System.Windows.DependencyObject
Public ReadOnly Property Parent As DependencyObject

Property Value

DependencyObject

This element's logical parent.

Examples

The following example shows code that checks for an element's parent, and then uses property values from the parent to set properties on the child element to match. In this case these are properties that affect the rendering size.

private void OnUIReady(object sender, System.EventArgs e)
{
    LinePane.Width = ((StackPanel)LinePane.Parent).ActualWidth;
    LinePane.Height = ((StackPanel)LinePane.Parent).ActualHeight;
    DesignerPane.MouseLeave += new System.Windows.Input.MouseEventHandler(DesignerPane_MouseLeave);
    this.SizeChanged += new SizeChangedEventHandler(Window1_SizeChanged);
}

Private Sub OnUIReady(ByVal sender As Object, ByVal e As System.EventArgs)
    LinePane.Width = (CType(LinePane.Parent, StackPanel)).ActualWidth
    LinePane.Height = (CType(LinePane.Parent, StackPanel)).ActualHeight
    AddHandler DesignerPane.MouseLeave, AddressOf DesignerPane_MouseLeave
    AddHandler SizeChanged, AddressOf Window1_SizeChanged
End Sub

Remarks

Parent may be null in cases where an element was instantiated, but is not attached to any logical tree that eventually connects to the page level root element, or the application object.

Note that the logical parent of an element can potentially change depending on your application's functionality, and keeping the value of this property will not reflect that change. You typically should get the value immediately before you need it.

See Trees in WPF for more information about logical tree traversal, and the scenarios where using Parent as a technique of parent element discovery is appropriate.

The property engine will potentially recalculate all property values of an element when it is reparented, because some properties inherit values through the logical tree. The DataContext that applies for bindings can also change when elements are reparented.

Changing an element's parent is typically only done through manipulation of collections, by using dedicated add or remove methods, or through setting content properties of elements.

The most typical scenario for using the Parent property is to obtain a reference and then get various FrameworkElement property values from the parent. For templates, the Parent of the template eventually will be null. To get past this point and extend into the logical tree where the template is actually applied, use TemplatedParent.

Note that this property does not report visual tree parents in cases where these vary from the logical tree parents. Visual tree parents are not typically important for general application cases but may be the desired parent elements for certain visual level cases. See VisualTreeHelper.

Applies to

See also