VisualElement Class
Definition
Important
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A Element that occupies an area on the screen, has a visual appearance, and can obtain touch input.
public class VisualElement : Xamarin.Forms.NavigableElement, Xamarin.Forms.IAnimatable, Xamarin.Forms.ITabStopElement, Xamarin.Forms.IVisualElementController
type VisualElement = class
inherit NavigableElement
interface IAnimatable
interface IVisualElementController
interface IElementController
interface ITabStopElement
- Inheritance
- Derived
- Implements
Remarks
The base class for most Xamarin.Forms on-screen elements. Provides most properties, events, and methods for presenting an item on screen.
Constructors
VisualElement() |
Fields
AnchorXProperty |
Identifies the AnchorX bindable property. |
AnchorYProperty |
Identifies the AnchorY bindable property. |
BackgroundColorProperty |
Identifies the BackgroundColor bindable property. |
BackgroundProperty | |
BehaviorsProperty |
Identifies the Behaviors bindable property. |
ClipProperty | |
FlowDirectionProperty |
Backing store for the FlowDirection property. |
HeightProperty |
Identifies the Height bindable property. |
HeightRequestProperty |
Backing store for the HeightRequest property. |
InputTransparentProperty |
Identifies the InputTransparent bindable property. |
IsEnabledProperty |
Identifies the IsEnabled bindable property. |
IsFocusedProperty |
Identifies the IsFocused bindable property. |
IsFocusedPropertyKey |
For internal use by the Xamarin.Forms platform. |
IsTabStopProperty |
The backing store for the IsTabStop field. |
IsVisibleProperty |
Identifies the IsVisible bindable property. |
MinimumHeightRequestProperty |
Backing store for the MinimumHeightRequest property. |
MinimumWidthRequestProperty |
Backing store for the MinimumWidthRequest property. |
NavigationProperty | |
OpacityProperty |
Identifies the Opacity bindable property. |
RotationProperty |
Identifies the Rotation bindable property. |
RotationXProperty |
Identifies the RotationX bindable property. |
RotationYProperty |
Identifies the RotationY bindable property. |
ScaleProperty |
Identifies the Scale bindable property. |
ScaleXProperty |
Backing store for the ScaleX property. |
ScaleYProperty |
Backing store for the ScaleY property. |
StyleProperty | |
TabIndexProperty |
The backing store for the TabIndex field. |
TranslationXProperty |
Identifies the TranslationX bindable property. |
TranslationYProperty |
Identifies the TranslationY bindable property. |
TriggersProperty |
Identifies the Triggers bindable property. |
VisualProperty |
The backing store for the Visual field. |
WidthProperty |
Identifies the Width bindable property. |
WidthRequestProperty |
Backing store for the WidthRequest property. |
XProperty |
Identifies the X bindable property. |
YProperty |
Identifies the Y bindable property. |
Properties
AnchorX |
Gets or sets the X component of the center point for any transform, relative to the bounds of the element. This is a bindable property. |
AnchorY |
Gets or sets the Y component of the center point for any transform, relative to the bounds of the element. This is a bindable property. |
AutomationId |
Gets or sets a value that allows the automation framework to find and interact with this element. (Inherited from Element) |
Background | |
BackgroundColor |
Gets or sets the color which will fill the background of a VisualElement. This is a bindable property. |
Batched |
For internal use by the Xamarin.Forms platform. |
Behaviors |
Gets the list of Behaviors associated to this element. This is a bindable property. |
BindingContext |
Gets or sets object that contains the properties that will be targeted by the bound properties that belong to this BindableObject. (Inherited from BindableObject) |
Bounds |
Gets the bounds of the element. |
class | (Inherited from NavigableElement) |
ClassId |
Gets or sets a value used to identify a collection of semantically similar elements. (Inherited from Element) |
Clip | |
DisableLayout |
For internal use by the Xamarin.Forms platform. |
Dispatcher | (Inherited from BindableObject) |
EffectControlProvider |
For internal use by the Xamarin.Forms platform. (Inherited from Element) |
Effects |
A list of the effects that are applied to this item. (Inherited from Element) |
FlowDirection |
Gets or sets the layout flow direction. |
Height |
Gets the current rendered height of this element. This is a read-only bindable property. |
HeightRequest |
Gets or sets the desired height override of this element. |
Id |
Gets a value that can be used to uniquely identify an element through the run of an application. (Inherited from Element) |
InputTransparent |
Gets or sets a value indicating whether this element should be involved in the user interaction cycle. This is a bindable property. |
IsEnabled |
Gets or sets a value indicating whether this element is enabled in the user interface. This is a bindable property. |
IsFocused |
Gets a value indicating whether this element is focused currently. This is a bindable property. |
IsInNativeLayout |
For internal use by the Xamarin.Forms platform. |
IsNativeStateConsistent |
For internal use by the Xamarin.Forms platform. |
IsPlatformEnabled |
For internal use by the Xamarin.Forms platform. |
IsTabStop |
Gets or sets a value that indicates whether this element is included in tab navigation. This is a bindable property. |
IsVisible |
Gets or sets a value that determines whether this elements should be part of the visual tree or not. This is a bindable property. |
LogicalChildren |
For internal use by the Xamarin.Forms platform. (Inherited from Element) |
MinimumHeightRequest |
Gets or sets a value which overrides the minimum height the element will request during layout. |
MinimumWidthRequest |
Gets or sets a value which overrides the minimum width the element will request during layout. |
Navigation | (Inherited from NavigableElement) |
NavigationProxy | (Inherited from NavigableElement) |
Opacity |
Gets or sets the opacity value applied to the element when it is rendered. This is a bindable property. |
Parent |
Gets or sets the parent element of the element. (Inherited from Element) |
ParentView |
Obsolete.
Gets the element which is the closest ancestor of this element that is a VisualElement. (Inherited from Element) |
Platform |
Obsolete.
(Inherited from Element)
|
RealParent |
For internal use by the Xamarin.Forms platform. (Inherited from Element) |
Resources |
Gets or sets the local resource dictionary. |
Rotation |
Gets or sets the rotation (in degrees) about the Z-axis (affine rotation) when the element is rendered. |
RotationX |
Gets or sets the rotation (in degrees) about the X-axis (perspective rotation) when the element is rendered. |
RotationY |
Gets or sets the rotation (in degrees) about the Y-axis (perspective rotation) when the element is rendered. |
Scale |
Gets or sets the scale factor applied to the element. |
ScaleX |
Gets or sets a scale value to apply to the X direction. |
ScaleY |
Gets or sets a scale value to apply to the Y direction. |
Style | (Inherited from NavigableElement) |
StyleClass | (Inherited from NavigableElement) |
StyleId |
Gets or sets a user defined value to uniquely identify the element. (Inherited from Element) |
TabIndex | |
TranslationX |
Gets or sets the X translation delta of the element. |
TranslationY |
Gets or sets the Y translation delta of the element. |
Triggers |
Gets the list of Trigger associated to this element. This is a bindable property. |
Visual | |
Width |
Gets the current rendered width of this element. This is a read-only bindable property. |
WidthRequest |
Gets or sets the desired width override of this element. |
X |
Gets the current X position of this element. This is a read-only bindable property. |
Y |
Gets the current Y position of this element. This is a read-only bindable property. |
Methods
ApplyBindings() |
Apply the bindings to BindingContext. (Inherited from BindableObject) |
BatchBegin() |
Signals the start of a batch of changes to the elements properties. |
BatchCommit() |
Signals the end of a batch of commands to the element and that those commands should now be committed. |
ChangeVisualState() |
For internal use by the Xamarin.Forms platform. |
ClearValue(BindableProperty) |
Clears any value set by SetValue for |
ClearValue(BindablePropertyKey) |
Clears any value set by SetValue for the property that is identified by |
CoerceValue(BindableProperty) | (Inherited from BindableObject) |
CoerceValue(BindablePropertyKey) | (Inherited from BindableObject) |
Descendants() |
For internal use by the Xamarin.Forms platform. (Inherited from Element) |
EffectIsAttached(String) |
For internal use by the Xamarin.Forms platform. (Inherited from Element) |
FindByName(String) |
Returns the element that has the specified name. (Inherited from Element) |
Focus() |
Attemps to set focus to this element. |
GetSizeRequest(Double, Double) |
Obsolete.
Returns the SizeRequest of the element. Calling this method begins the measure pass of a layout cycle. |
GetValue(BindableProperty) |
Returns the value that is contained in the BindableProperty. (Inherited from BindableObject) |
GetValues(BindableProperty, BindableProperty) |
Obsolete.
For internal use by the Xamarin.Forms platform. (Inherited from BindableObject) |
GetValues(BindableProperty, BindableProperty, BindableProperty) |
Obsolete.
For internal use by the Xamarin.Forms platform. (Inherited from BindableObject) |
InvalidateMeasure() |
Method that is called to invalidate the layout of this VisualElement. Raises the MeasureInvalidated event. |
InvalidateMeasureNonVirtual(InvalidationTrigger) |
For internal use by the Xamarin.Forms platform. |
IsSet(BindableProperty) |
Returns |
Layout(Rectangle) |
Updates the bounds of the element during the layout cycle. |
Measure(Double, Double, MeasureFlags) |
Returns the minimum size that a visual element needs in order to be displayed on the device. |
NativeSizeChanged() |
For internal use by the Xamarin.Forms platform. |
OnBindingContextChanged() | |
OnChildAdded(Element) |
Application developers can override this method to respond when a child is added. |
OnChildRemoved(Element) |
Obsolete.
Application developers can override this method to respond when a child is removed. |
OnChildRemoved(Element, Int32) | |
OnChildrenReordered() |
Invoked whenever the ChildrenReordered event is about to be emitted. Implement this method to add class handling for this event. |
OnMeasure(Double, Double) |
Method that is called when a layout measurement happens. |
OnParentSet() | (Inherited from NavigableElement) |
OnPropertyChanged(String) |
Method that is called when a bound property is changed. (Inherited from Element) |
OnPropertyChanging(String) |
Call this method from a child class to notify that a change is going to happen on a property. (Inherited from BindableObject) |
OnSizeAllocated(Double, Double) |
This method is called when the size of the element is set during a layout cycle. This method is called directly before the SizeChanged event is emitted. Implement this method to add class handling for this event. |
OnSizeRequest(Double, Double) |
Obsolete.
This method is called during the measure pass of a layout cycle to get the desired size of an element. |
OnTabIndexPropertyChanged(Int32, Int32) | |
OnTabStopPropertyChanged(Boolean, Boolean) | |
RemoveBinding(BindableProperty) |
Removes a previously set binding. (Inherited from BindableObject) |
RemoveDynamicResource(BindableProperty) |
Removes a previously set dynamic resource (Inherited from Element) |
SetBinding(BindableProperty, BindingBase) |
Assigns a binding to a property. (Inherited from BindableObject) |
SetDynamicResource(BindableProperty, String) |
Sets the BindableProperty property of this element to be updated via the DynamicResource with the provided key. (Inherited from Element) |
SetValue(BindableProperty, Object) |
Sets the value of the specified property. (Inherited from BindableObject) |
SetValue(BindablePropertyKey, Object) |
Sets the value of the propertyKey. (Inherited from BindableObject) |
SetValueCore(BindableProperty, Object, SetValueFlags) |
For internal use by the Xamarin.Forms platform. (Inherited from BindableObject) |
SetValueFromRenderer(BindableProperty, Object) |
For internal use by the Xamarin.Forms platform. (Inherited from Element) |
SetValueFromRenderer(BindablePropertyKey, Object) |
For internal use by the Xamarin.Forms platform. (Inherited from Element) |
SizeAllocated(Double, Double) |
SizeAllocated is called during a layout cycle to signal the start of a sub-tree layout. |
TabIndexDefaultValueCreator() | |
TabStopDefaultValueCreator() | |
UnapplyBindings() |
Unapplies all previously set bindings. (Inherited from BindableObject) |
Unfocus() |
Unsets focus to this element. |
Events
BatchCommitted |
For internal use by the Xamarin.Forms platform. |
BindingContextChanged |
Raised whenever the BindingContext property changes. (Inherited from BindableObject) |
ChildAdded |
Occurs whenever a child element is added to the element. (Inherited from Element) |
ChildRemoved |
Occurs whenever a child element is removed from the element. (Inherited from Element) |
ChildrenReordered |
Occurs when the Children of a VisualElement have been re-ordered. |
DescendantAdded |
Occurs whenever a child element is added to the elements subtree. (Inherited from Element) |
DescendantRemoved |
Occurs whenever a child element is removed from the elements subtree. (Inherited from Element) |
FocusChangeRequested |
For internal use by the Xamarin.Forms platform. |
Focused |
Occurs when the element receives focus. |
MeasureInvalidated |
Event that is raised when the layout of a visual element is invalidated. |
PlatformSet |
Obsolete.
(Inherited from Element)
|
PropertyChanged |
Raised when a property has changed. (Inherited from BindableObject) |
PropertyChanging |
Raised when a property is about to change. (Inherited from BindableObject) |
SizeChanged |
Occurs when either the Width or the Height properties change value on this element. |
Unfocused |
Occurs when the element loses focus. |
Explicit Interface Implementations
IDynamicResourceHandler.SetDynamicResource(BindableProperty, String) |
For internal use by the Xamarin.Forms platform. (Inherited from BindableObject) |
IElementController.SetValueFromRenderer(BindableProperty, Object) |
For internal use by the Xamarin.Forms platform. (Inherited from Element) |
INameScope.RegisterName(String, Object) |
For internal use only. (Inherited from Element) |
IVisualElementController.EffectiveFlowDirection |
Gets the effective visual flow direction for the element on the platform, taking into account the locale and logical flow settings. |
IVisualElementController.InvalidateMeasure(InvalidationTrigger) |
This method is for internal use. |