Track.ViewportSize Property

 

Gets or sets the size of the part of the scrollable content that is visible.

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

Public Property ViewportSize As Double

Property Value

Type: System.Double

The size of the visible area of the scrollable content. The default is Double.NaN, which means that the content size is not defined.

The value of the ViewportSize property is used to calculate the size of the Thumb control in a ScrollBar when the ViewportSize is not Double.NaN. For more information, see the remarks for the Thumb property.

To explicitly define the size of the Thumb, create an object that derives from the Track class and provide overrides for MeasureOverride and ArrangeOverride.

If you implement a Track as part of a ScrollBar control and you do not explicitly set the Track.ViewportSize property, the Track.ViewportSize property binds to the ScrollBar.ViewportSize property.

The value of the ViewportSize property of a Track control that is implemented in a Slider control is always Double.NaN, because the Thumb control does not change size.

Identifier field

ViewportSizeProperty

Metadata properties set to true

AffectsArrange

.NET Framework
Available since 3.0
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