FrameworkElement.ActualHeight Property
Gets the rendered height of this element.
Assembly: PresentationFramework (in PresentationFramework.dll)
Property Value
Type: System.DoubleThe element's height, as a value in device-independent units (1/96th inch per unit). The default value is 0 (zero).
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.
The following example displays various height properties.
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
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.