FrameworkElement.ActualHeight Property (System.Windows)

Microsoft Developer Network

ActualHeight Property

.NET Framework Class Library

FrameworkElement..::.ActualHeight Property

Gets the rendered height of this element. This is a dependency property.

Namespace: System.Windows
Assembly: PresentationFramework (in PresentationFramework.dll)

Syntax

Visual Basic (Declaration)

Public ReadOnly Property ActualHeight As Double

Visual Basic (Usage)

Dim instance As FrameworkElement
Dim value As Double

value = instance.ActualHeight

public double ActualHeight { get; }

Visual C++

public:
property double ActualHeight {
    double get ();
}

JScript

public function get ActualHeight () : double

XAML

You cannot set this property in XAML.

Property Value

Type: System..::.Double
The element's height, as a value in device-independent units (1/96th inch per unit). The default value is 0 (zero).

Dependency Property Information

Identifier field	ActualHeightProperty
Metadata properties set to true	None

Remarks

This property is a calculated value based on other height inputs, and the layout system. The value is set by the layout system itself, based on an actual rendering pass, and may therefore lag slightly behind the set value of properties such as Height that are the basis of the input change.

Because ActualHeight is a calculated value, you should be aware that there could be multiple or incremental reported changes to it as a result of various operations by the layout system. The layout system may be calculating required measure space for child elements, constraints by the parent element, and so on.

Although you cannot set this property from XAML, you can base a Trigger upon its value in a style.

Examples

The following example displays various height properties.

Visual Basic

Private Sub changeHeight(ByVal sender As Object, ByVal args As SelectionChangedEventArgs)
    Dim li As ListBoxItem = CType(CType(sender, ListBox).SelectedItem, ListBoxItem)
    Dim sz1 As Double = Double.Parse(li.Content.ToString())
    rect1.Height = sz1
    rect1.UpdateLayout()
    txt1.Text = "ActualHeight is set to " + rect1.ActualHeight.ToString
    txt2.Text = "Height is set to " + rect1.Height.ToString
    txt3.Text = "MinHeight is set to " + rect1.MinHeight.ToString
    txt4.Text = "MaxHeight is set to " + rect1.MaxHeight.ToString
End Sub
Private Sub changeMinHeight(ByVal sender As Object, ByVal args As SelectionChangedEventArgs)

    Dim li As ListBoxItem = CType(CType(sender, ListBox).SelectedItem, ListBoxItem)
    Dim sz1 As Double = Double.Parse(li.Content.ToString())
    rect1.MinHeight = sz1
    rect1.UpdateLayout()
    txt1.Text = "ActualHeight is set to " + rect1.ActualHeight.ToString
    txt2.Text = "Height is set to " + rect1.Height.ToString
    txt3.Text = "MinHeight is set to " + rect1.MinHeight.ToString
    txt4.Text = "MaxHeight is set to " + rect1.MaxHeight.ToString
End Sub
Private Sub changeMaxHeight(ByVal sender As Object, ByVal args As SelectionChangedEventArgs)

    Dim li As ListBoxItem = CType(CType(sender, ListBox).SelectedItem, ListBoxItem)
    Dim sz1 As Double = Double.Parse(li.Content.ToString())
    rect1.MaxHeight = sz1
    rect1.UpdateLayout()
    txt1.Text = "ActualHeight is set to " + rect1.ActualHeight.ToString
    txt2.Text = "Height is set to " + rect1.Height.ToString
    txt3.Text = "MinHeight is set to " + rect1.MinHeight.ToString
    txt4.Text = "MaxHeight is set to " + rect1.MaxHeight.ToString
End Sub

private void changeHeight(object sender, SelectionChangedEventArgs args)
{
    ListBoxItem li = ((sender as ListBox).SelectedItem as ListBoxItem);
    Double sz1 = Double.Parse(li.Content.ToString());
    rect1.Height = sz1;
    rect1.UpdateLayout();
    txt1.Text= "ActualHeight is set to " + rect1.ActualHeight;
    txt2.Text= "Height is set to " + rect1.Height;
    txt3.Text= "MinHeight is set to " + rect1.MinHeight;
    txt4.Text= "MaxHeight is set to " + rect1.MaxHeight;
}
private void changeMinHeight(object sender, SelectionChangedEventArgs args)
{
    ListBoxItem li = ((sender as ListBox).SelectedItem as ListBoxItem);
    Double sz1 = Double.Parse(li.Content.ToString());
    rect1.MinHeight = sz1;
    rect1.UpdateLayout();
    txt1.Text= "ActualHeight is set to " + rect1.ActualHeight;
    txt2.Text= "Height is set to " + rect1.Height;
    txt3.Text= "MinHeight is set to " + rect1.MinHeight;
    txt4.Text= "MaxHeight is set to " + rect1.MaxHeight;
}
private void changeMaxHeight(object sender, SelectionChangedEventArgs args)
{
    ListBoxItem li = ((sender as ListBox).SelectedItem as ListBoxItem);
    Double sz1 = Double.Parse(li.Content.ToString());
    rect1.MaxHeight = sz1;
    rect1.UpdateLayout();
    txt1.Text= "ActualHeight is set to " + rect1.ActualHeight;
    txt2.Text= "Height is set to " + rect1.Height;
    txt3.Text= "MinHeight is set to " + rect1.MinHeight;
    txt4.Text= "MaxHeight is set to " + rect1.MaxHeight;
}

Platforms

Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Version Information

.NET Framework

Supported in: 3.5, 3.0

Reference

FrameworkElement Class

FrameworkElement Members

System.Windows Namespace

Other Resources

Read-Only Dependency Properties