Content Model: Panel enforces a strong content model for child content. The Children collection of a Panel element can only consist of UIElement objects. Adding a UIElement child to a Panel implicitly adds it to the UIElementCollection for the Panel element.

WPF provides a comprehensive suite of derived Panel implementations, enabling many complex layouts. If you want to implement new layout containers, use the MeasureOverride and ArrangeOverride methods. For a demonstration of how to use these methods, see Create a Custom Content-Wrapping Panel Sample.

Panel elements do not receive mouse or stylus events if a Background is not defined. If you need to handle mouse or stylus events but do not want a background for your Panel, use Transparent.

Panel elements do not receive focus by default. To compel a panel element to receive focus, set the Focusable property to true.

This example shows how to override the default layout behavior of the Panel element and create custom layout elements that are derived from Panel.

The example defines a simple custom Panel element called PlotPanel, which positions child elements according to two hard-coded x- and y-coordinates. In this example, x and y are both set to 50; therefore, all child elements are positioned at that location on the x and y axes.

To implement custom Panel behaviors, the example uses the MeasureOverride and ArrangeOverride methods. Each method returns the Size data that is necessary to position and render child elements.

Public Class PlotPanel
    Inherits Panel
    'Override the default Measure method of Panel.

    Protected Overrides Function MeasureOverride(ByVal availableSize As System.Windows.Size) As System.Windows.Size
        Dim childSize As Size = CType(availableSize, Size)
        For Each child As UIElement In InternalChildren
            child.Measure(childSize)
        Next
        Return MyBase.MeasureOverride(availableSize)
    End Function
    Protected Overrides Function ArrangeOverride(ByVal finalSize As System.Windows.Size) As System.Windows.Size
        For Each child As UIElement In InternalChildren
            Dim x As Double = 50
            Dim y As Double = 50
            child.Arrange(New Rect(New System.Windows.Point(x, y), child.DesiredSize))
        Next
        Return MyBase.ArrangeOverride(finalSize)
    End Function
End Class

For the complete sample, see Create a Simple Custom Panel Sample.

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

.NET Framework

Reference

Other Resources