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  • Artykuł

VirtualizingPanel Class

Microsoft Silverlight will reach end of support after October 2021. Learn more.

Provides a framework for Panel elements that virtualize their visual children.

Inheritance Hierarchy

System.Object
  System.Windows.DependencyObject
    System.Windows.UIElement
      System.Windows.FrameworkElement
        System.Windows.Controls.Panel
          System.Windows.Controls.VirtualizingPanel
            Microsoft.Internal.Pivot.Controls.SeahorseItemVirtualizingPanel
            System.Windows.Controls.VirtualizingStackPanel

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

Syntax

'Declaration
Public MustInherit Class VirtualizingPanel _
    Inherits Panel

public abstract class VirtualizingPanel : Panel

The VirtualizingPanel type exposes the following members.

Constructors

  Name Description
Protected methodSupported by Silverlight for Windows Phone VirtualizingPanel Initializes a new instance of the VirtualizingPanel class.

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Properties

  Name Description
Public propertySupported by Silverlight for Windows Phone ActualHeight Gets the rendered height of a FrameworkElement. (Inherited from FrameworkElement.)
Public propertySupported by Silverlight for Windows Phone ActualWidth Gets the rendered width of a FrameworkElement. (Inherited from FrameworkElement.)
Public propertySupported by Silverlight for Windows Phone AllowDrop Gets or sets a value that determines whether this UIElement can be a drop target for purposes of Silverlight drag-and-drop operations. (Inherited from UIElement.)
Public propertySupported by Silverlight for Windows Phone Background Gets or sets a Brush that is used to fill the panel. (Inherited from Panel.)
Public propertySupported by Silverlight for Windows Phone CacheMode Gets or sets a value that indicates that rendered content should be cached when possible. (Inherited from UIElement.)
Public propertySupported by Silverlight for Windows Phone Children Gets the collection of child elements of the panel. (Inherited from Panel.)
Public propertySupported by Silverlight for Windows Phone Clip Gets or sets the Geometry used to define the outline of the contents of a UIElement. (Inherited from UIElement.)
Public propertySupported by Silverlight for Windows Phone Cursor Gets or sets the cursor image that displays while the mouse pointer is over a FrameworkElement. (Inherited from FrameworkElement.)
Public propertySupported by Silverlight for Windows Phone DataContext Gets or sets the data context for a FrameworkElement when it participates in data binding. (Inherited from FrameworkElement.)
Public propertySupported by Silverlight for Windows Phone DesiredSize Gets the size that this UIElement computed during the measure pass of the layout process. (Inherited from UIElement.)
Public propertySupported by Silverlight for Windows Phone Dispatcher Gets the Dispatcher this object is associated with. (Inherited from DependencyObject.)
Public property Effect Gets or sets the pixel shader effect to use for rendering this UIElement. (Inherited from UIElement.)
Public propertySupported by Silverlight for Windows Phone FlowDirection Gets or sets the direction that text and other user interface elements flow within any parent element that controls their layout. (Inherited from FrameworkElement.)
Public propertySupported by Silverlight for Windows Phone Height Gets or sets the suggested height of a FrameworkElement. (Inherited from FrameworkElement.)
Public propertySupported by Silverlight for Windows Phone HorizontalAlignment Gets or sets the horizontal alignment characteristics that are applied to a FrameworkElement when it is composed in a layout parent, such as a panel or items control. (Inherited from FrameworkElement.)
Public propertySupported by Silverlight for Windows Phone IsHitTestVisible Gets or sets whether the contained area of this UIElement can return true values for hit testing. (Inherited from UIElement.)
Public propertySupported by Silverlight for Windows Phone IsItemsHost Gets a value that indicates whether this Panel is a container for UI items that are generated by an ItemsControl. (Inherited from Panel.)
Public propertySupported by Silverlight for Windows Phone ItemContainerGenerator Gets a value that identifies the ItemContainerGenerator for this VirtualizingPanel.
Public propertySupported by Silverlight for Windows Phone Language Gets or sets localization/globalization language information that applies to a FrameworkElement. (Inherited from FrameworkElement.)
Public propertySupported by Silverlight for Windows Phone Margin Gets or sets the outer margin of a FrameworkElement. (Inherited from FrameworkElement.)
Public propertySupported by Silverlight for Windows Phone MaxHeight Gets or sets the maximum height constraint of a FrameworkElement. (Inherited from FrameworkElement.)
Public propertySupported by Silverlight for Windows Phone MaxWidth Gets or sets the maximum width constraint of a FrameworkElement. (Inherited from FrameworkElement.)
Public propertySupported by Silverlight for Windows Phone MinHeight Gets or sets the minimum height constraint of a FrameworkElement. (Inherited from FrameworkElement.)
Public propertySupported by Silverlight for Windows Phone MinWidth Gets or sets the minimum width constraint of a FrameworkElement. (Inherited from FrameworkElement.)
Public propertySupported by Silverlight for Windows Phone Name Gets or sets the identifying name of the object. When a XAML processor creates the object tree from XAML markup, run-time code can refer to the XAML-declared object by this name. (Inherited from FrameworkElement.)
Public propertySupported by Silverlight for Windows Phone Opacity Gets or sets the degree of the object's opacity. (Inherited from UIElement.)
Public propertySupported by Silverlight for Windows Phone OpacityMask Gets or sets the brush used to alter the opacity of regions of this object. (Inherited from UIElement.)
Public propertySupported by Silverlight for Windows Phone Parent Gets the parent object of this FrameworkElement in the object tree. (Inherited from FrameworkElement.)
Public propertySupported by Silverlight for Windows Phone Projection Gets or sets the perspective projection (3-D effect) to apply when rendering this UIElement. (Inherited from UIElement.)
Public propertySupported by Silverlight for Windows Phone RenderSize Gets the final render size of a UIElement. (Inherited from UIElement.)
Public propertySupported by Silverlight for Windows Phone RenderTransform Gets or sets transform information that affects the rendering position of a UIElement. (Inherited from UIElement.)
Public propertySupported by Silverlight for Windows Phone RenderTransformOrigin Gets or sets the origin point of any possible render transform declared by RenderTransform, relative to the bounds of the UIElement. (Inherited from UIElement.)
Public propertySupported by Silverlight for Windows Phone Resources Gets the locally defined resource dictionary. In XAML, you can establish resource items as child object elements of a frameworkElement.Resources property element, through XAML implicit collection syntax. (Inherited from FrameworkElement.)
Public propertySupported by Silverlight for Windows Phone Style Gets or sets an instance Style that is applied for this object during rendering. (Inherited from FrameworkElement.)
Public propertySupported by Silverlight for Windows Phone Tag Gets or sets an arbitrary object value that can be used to store custom information about this object. (Inherited from FrameworkElement.)
Public propertySupported by Silverlight for Windows Phone Triggers Gets the collection of triggers for animations that are defined for a FrameworkElement. (Inherited from FrameworkElement.)
Public propertySupported by Silverlight for Windows Phone UseLayoutRounding Gets or sets a value that determines whether rendering for the object and its visual subtree should use rounding behavior that aligns rendering to whole pixels. (Inherited from UIElement.)
Public propertySupported by Silverlight for Windows Phone VerticalAlignment Gets or sets the vertical alignment characteristics that are applied to a FrameworkElement when it is composed in a parent object such as a panel or items control. (Inherited from FrameworkElement.)
Public propertySupported by Silverlight for Windows Phone Visibility Gets or sets the visibility of a UIElement. A UIElement that is not visible does not render and does not communicate its desired size to layout. (Inherited from UIElement.)
Public propertySupported by Silverlight for Windows Phone Width Gets or sets the width of a FrameworkElement. (Inherited from FrameworkElement.)

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Methods

  Name Description
Public methodSupported by Silverlight for Windows Phone AddHandler Adds a routed event handler for a specified routed event, adding the handler to the handler collection on the current element. Specify handledEventsToo as true to have the provided handler be invoked for routed event that had already been marked as handled by another element along the event route. (Inherited from UIElement.)
Protected methodSupported by Silverlight for Windows Phone AddInternalChild Adds the specified UIElement to the Children collection of a VirtualizingPanel element.
Public methodSupported by Silverlight for Windows Phone Arrange Positions child objects and determines a size for a UIElement. Parent objects that implement custom layout for their child elements should call this method from their layout override implementations to form a recursive layout update. (Inherited from UIElement.)
Protected methodSupported by Silverlight for Windows Phone ArrangeOverride Provides the behavior for the Arrange pass of Silverlight layout. Classes can override this method to define their own Arrange pass behavior. (Inherited from FrameworkElement.)
Protected methodSupported by Silverlight for Windows Phone BringIndexIntoView When implemented in a derived class, generates the item at the specified index location and makes it visible.
Public methodSupported by Silverlight for Windows Phone CaptureMouse Sets mouse capture to a UIElement. (Inherited from UIElement.)
Public methodSupported by Silverlight for Windows Phone CheckAccess Determines whether the calling thread has access to this object. (Inherited from DependencyObject.)
Public methodSupported by Silverlight for Windows Phone ClearValue Clears the local value of a dependency property. (Inherited from DependencyObject.)
Public methodSupported by Silverlight for Windows Phone Equals(Object) Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Protected methodSupported by Silverlight for Windows Phone Finalize Allows an object to try to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection. (Inherited from Object.)
Public methodSupported by Silverlight for Windows Phone FindName Retrieves an object that has the specified identifier name. (Inherited from FrameworkElement.)
Public methodSupported by Silverlight for Windows Phone GetAnimationBaseValue Returns any base value established for a Silverlight dependency property, which would apply in cases where an animation is not active. (Inherited from DependencyObject.)
Public methodSupported by Silverlight for Windows Phone GetBindingExpression Retrieves the BindingExpression for a dependency property where a binding is established. (Inherited from FrameworkElement.)
Public methodSupported by Silverlight for Windows Phone GetHashCode Serves as a hash function for a particular type. (Inherited from Object.)
Public methodSupported by Silverlight for Windows Phone GetType Gets the Type of the current instance. (Inherited from Object.)
Public methodSupported by Silverlight for Windows Phone GetValue Returns the current effective value of a dependency property from a DependencyObject. (Inherited from DependencyObject.)
Protected methodSupported by Silverlight for Windows Phone InsertInternalChild Adds the specified UIElement to the collection of a VirtualizingPanel element at the specified index position.
Public methodSupported by Silverlight for Windows Phone InvalidateArrange Invalidates the arrange state (layout) for a UIElement. After the invalidation, the UIElement will have its layout updated, which will occur asynchronously. (Inherited from UIElement.)
Public methodSupported by Silverlight for Windows Phone InvalidateMeasure Invalidates the measurement state (layout) for a UIElement. (Inherited from UIElement.)
Public methodSupported by Silverlight for Windows Phone Measure Updates the DesiredSize of a UIElement. Typically, objects that implement custom layout for their layout children call this method from their own MeasureOverride implementations to form a recursive layout update. (Inherited from UIElement.)
Protected methodSupported by Silverlight for Windows Phone MeasureOverride Provides the behavior for the Measure pass of Silverlight layout. Classes can override this method to define their own Measure pass behavior. (Inherited from FrameworkElement.)
Protected methodSupported by Silverlight for Windows Phone MemberwiseClone Creates a shallow copy of the current Object. (Inherited from Object.)
Public methodSupported by Silverlight for Windows Phone OnApplyTemplate When overridden in a derived class, is invoked whenever application code or internal processes (such as a rebuilding layout pass) call ApplyTemplate. In simplest terms, this means the method is called just before a UI element displays in an application. For more information, see Remarks. (Inherited from FrameworkElement.)
Protected methodSupported by Silverlight for Windows Phone OnClearChildren Called when the collection of child elements is cleared by the base Panel class.
Protected methodSupported by Silverlight for Windows Phone OnCreateAutomationPeer When implemented in a derived class, returns class-specific AutomationPeer implementations for the Silverlight automation infrastructure. (Inherited from UIElement.)
Protected methodSupported by Silverlight for Windows Phone OnItemsChanged Called when the Items collection that is associated with the ItemsControl for this Panel changes.
Public methodSupported by Silverlight for Windows Phone ReadLocalValue Returns the local value of a dependency property, if a local value is set. (Inherited from DependencyObject.)
Public methodSupported by Silverlight for Windows Phone ReleaseMouseCapture Removes mouse capture from a UIElement. After this call, typically no object holds mouse capture. (Inherited from UIElement.)
Public methodSupported by Silverlight for Windows Phone RemoveHandler Removes the specified routed event handler from this UIElement. (Inherited from UIElement.)
Protected methodSupported by Silverlight for Windows Phone RemoveInternalChildRange Removes child elements from the Children collection.
Public methodSupported by Silverlight for Windows Phone SetBinding Attaches a binding to a FrameworkElement, using the provided binding object, and returns a BindingExpressionBase for possible later use. (Inherited from FrameworkElement.)
Public methodSupported by Silverlight for Windows Phone SetValue Sets the local value of a dependency property on a DependencyObject. (Inherited from DependencyObject.)
Public methodSupported by Silverlight for Windows Phone ToString Returns a string that represents the current object. (Inherited from Object.)
Public methodSupported by Silverlight for Windows Phone TransformToVisual Returns a transform object that can be used to transform coordinates from the UIElement to the specified object. (Inherited from UIElement.)
Public methodSupported by Silverlight for Windows Phone UpdateLayout Ensures that all positions of child objects of a UIElement are properly updated for layout. (Inherited from UIElement.)

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Events

  Name Description
Public eventSupported by Silverlight for Windows Phone BindingValidationError Occurs when a data validation error is reported by a binding source. (Inherited from FrameworkElement.)
Public event DataContextChanged Occurs when the data context for this element changes. (Inherited from FrameworkElement.)
Public eventSupported by Silverlight for Windows Phone DoubleTap Occurs when a DoubleTap gesture is committed while over this UIElement. (Inherited from UIElement.)
Public event DragEnter Occurs when the input system reports an underlying drag event with this element as the target. (Inherited from UIElement.)
Public event DragLeave Occurs when the input system reports an underlying drag event with this element as the origin. (Inherited from UIElement.)
Public event DragOver Occurs when the input system reports an underlying drag event with this element as the potential drop target. (Inherited from UIElement.)
Public event Drop Occurs when the input system reports an underlying drop event with this element as the drop target. (Inherited from UIElement.)
Public eventSupported by Silverlight for Windows Phone GotFocus Occurs when a UIElement receives focus. (Inherited from UIElement.)
Public eventSupported by Silverlight for Windows Phone Hold Occurs when a Hold gesture is committed while over this UIElement. (Inherited from UIElement.)
Public eventSupported by Silverlight for Windows Phone KeyDown Occurs when a keyboard key is pressed while the UIElement has focus. (Inherited from UIElement.)
Public eventSupported by Silverlight for Windows Phone KeyUp Occurs when a keyboard key is released while the UIElement has focus. (Inherited from UIElement.)
Public eventSupported by Silverlight for Windows Phone LayoutUpdated Occurs when the layout of the Silverlight visual tree changes. (Inherited from FrameworkElement.)
Public eventSupported by Silverlight for Windows Phone Loaded Occurs when a FrameworkElement has been constructed and added to the object tree. (Inherited from FrameworkElement.)
Public eventSupported by Silverlight for Windows Phone LostFocus Occurs when a UIElement loses focus. (Inherited from UIElement.)
Public eventSupported by Silverlight for Windows Phone LostMouseCapture Occurs when the UIElement loses mouse capture. (Inherited from UIElement.)
Public eventSupported by Silverlight for Windows Phone ManipulationCompleted Occurs when a manipulation and inertia on the UIElement is complete. (Inherited from UIElement.)
Public eventSupported by Silverlight for Windows Phone ManipulationDelta Occurs when the input device changes position during a manipulation. (Inherited from UIElement.)
Public eventSupported by Silverlight for Windows Phone ManipulationStarted Occurs when an input device begins a manipulation on the UIElement. (Inherited from UIElement.)
Public event MediaCommand Occurs when a button is pressed on a remote control. (Inherited from UIElement.)
Public eventSupported by Silverlight for Windows Phone MouseEnter Occurs when the mouse (or a stylus) enters the bounding area of a UIElement. (Inherited from UIElement.)
Public eventSupported by Silverlight for Windows Phone MouseLeave Occurs when the mouse (or the stylus) leaves the bounding area of a UIElement. (Inherited from UIElement.)
Public eventSupported by Silverlight for Windows Phone MouseLeftButtonDown Occurs when the left mouse button is pressed (or when the tip of the stylus touches the tablet) while the mouse pointer is over a UIElement. (Inherited from UIElement.)
Public eventSupported by Silverlight for Windows Phone MouseLeftButtonUp Occurs when the left mouse button is released (or the tip of the stylus is removed from the tablet) while the mouse (or the stylus) is over a UIElement (or while a UIElement holds mouse capture). (Inherited from UIElement.)
Public eventSupported by Silverlight for Windows Phone MouseMove Occurs when the coordinate position of the mouse (or stylus) changes while over a UIElement (or while a UIElement holds mouse capture). (Inherited from UIElement.)
Public event MouseRightButtonDown Occurs when the right mouse button is pressed while the mouse pointer is over a UIElement. (Inherited from UIElement.)
Public event MouseRightButtonUp Occurs when the right mouse button is released while the mouse pointer is over a UIElement. However, this event will only be raised if a caller marks the preceding MouseRightButtonDown event as handled; see Remarks. (Inherited from UIElement.)
Public eventSupported by Silverlight for Windows Phone MouseWheel Occurs when the user rotates the mouse wheel while the mouse pointer is over a UIElement, or the UIElement has focus. (Inherited from UIElement.)
Public eventSupported by Silverlight for Windows Phone SizeChanged Occurs when either the ActualHeight or the ActualWidth properties change value on a FrameworkElement. (Inherited from FrameworkElement.)
Public eventSupported by Silverlight for Windows Phone Tap Occurs when a Tap gesture is committed while over this UIElement. (Inherited from UIElement.)
Public eventSupported by Silverlight for Windows Phone TextInput Occurs when a UI element gets text in a device-independent manner. (Inherited from UIElement.)
Public eventSupported by Silverlight for Windows Phone TextInputStart Occurs when a UI element initially gets text in a device-independent manner. (Inherited from UIElement.)
Public eventSupported by Silverlight for Windows Phone TextInputUpdate Occurs when text continues to be composed via an input method editor (IME). (Inherited from UIElement.)
Public eventSupported by Silverlight for Windows Phone Unloaded Occurs when this object is no longer connected to the main object tree. (Inherited from FrameworkElement.)

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Remarks

It is intensive, both in terms of memory and processor, to generate a large number of UI elements when only a few may be on the screen at a given time. Virtualization refers to a technique by which a subset of UI elements are generated from a larger number of data items based on which items are visible on the screen. Through functionality that is provided by VirtualizingPanel, VirtualizingStackPanel calculates visible items and works with the ItemContainerGenerator from an ItemsControl (such as ListBox) to only create UI elements for visible items.

Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.