Element Class
Definition
Important
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Provides the base class for all Xamarin.Forms hierarchal elements. This class contains all the methods and properties required to represent an element in the Xamarin.Forms hierarchy.
public abstract class Element : Xamarin.Forms.BindableObject, Xamarin.Forms.IElementController, Xamarin.Forms.Internals.INameScopetype Element = class
inherit BindableObject
interface INameScope
interface IElementController- Inheritance
- Derived
- Implements
Remarks
Important categories of visual elements are noted in the following table:
| Class | Description |
|---|---|
| VisualElement | A Element that occupies an area on the screen, has a visual appearance, and can obtain touch input. |
| Cell | Cells are elements meant to be added to ListView or TableView. |
| Page | A VisualElement that occupies most or all of the screen and contains a single child. |
| Layout | Layout have a single child of type View, while subclasses of Layout<T> have a collection of multiple children views, including other layouts. |
| Controls and specialized Views | The lower part of the diagram shows the Xamarin.Forms classes for universally-available controls, such as Buttons and TableViews. |
Constructors
| Element() |
Protected constructor used to initialize a the element. |
Fields
| AutomationIdProperty |
The backing store for the AutomationId field. |
| ClassIdProperty |
Identifies the ClassId bindable property. |
| MenuProperty |
Backing store for the attached menu property. |
Properties
| AutomationId |
Gets or sets a value that allows the automation framework to find and interact with this element. |
| 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) |
| ClassId |
Gets or sets a value used to identify a collection of semantically similar elements. |
| Dispatcher | (Inherited from BindableObject) |
| EffectControlProvider |
For internal use by the Xamarin.Forms platform. |
| Effects |
A list of the effects that are applied to this item. |
| Id |
Gets a value that can be used to uniquely identify an element through the run of an application. |
| LogicalChildren |
For internal use by the Xamarin.Forms platform. |
| Parent |
Gets or sets the parent element of the element. |
| ParentView |
Obsolete.
Gets the element which is the closest ancestor of this element that is a VisualElement. |
| Platform | |
| RealParent |
For internal use by the Xamarin.Forms platform. |
| StyleId |
Gets or sets a user defined value to uniquely identify the element. |
Methods
| ApplyBindings() |
Apply the bindings to BindingContext. (Inherited from BindableObject) |
| 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. |
| EffectIsAttached(String) |
For internal use by the Xamarin.Forms platform. |
| FindByName(String) |
Returns the element that has the specified name. |
| GetMenu(BindableObject) |
Gets the Menu object for |
| 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) |
| IsSet(BindableProperty) |
Returns |
| OnBindingContextChanged() |
Invoked whenever the binding context of the element changes. Implement this method to add class handling for this event. |
| OnChildAdded(Element) |
Invoked whenever the ChildAdded event needs to be emitted. Implement this method to add class handling for this event. |
| OnChildRemoved(Element) |
Obsolete.
Invoked whenever the ChildRemoved event needs to be emitted. Implement this method to add class handling for this event. |
| OnChildRemoved(Element, Int32) | |
| OnParentSet() |
Invoked whenever the Parent of an element is set. Implement this method in order to add behavior when the element is added to a parent. |
| OnPropertyChanged(String) |
Method that is called when a bound property is changed. |
| OnPropertyChanging(String) |
Call this method from a child class to notify that a change is going to happen on a property. (Inherited from BindableObject) |
| RemoveBinding(BindableProperty) |
Removes a previously set binding. (Inherited from BindableObject) |
| RemoveDynamicResource(BindableProperty) |
Removes a previously set dynamic resource |
| 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. |
| SetMenu(BindableObject, Menu) |
Sets the menu for |
| 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. |
| SetValueFromRenderer(BindablePropertyKey, Object) |
For internal use by the Xamarin.Forms platform. |
| UnapplyBindings() |
Unapplies all previously set bindings. (Inherited from BindableObject) |
Events
| BindingContextChanged |
Raised whenever the BindingContext property changes. (Inherited from BindableObject) |
| ChildAdded |
Occurs whenever a child element is added to the element. |
| ChildRemoved |
Occurs whenever a child element is removed from the element. |
| DescendantAdded |
Occurs whenever a child element is added to the elements subtree. |
| DescendantRemoved |
Occurs whenever a child element is removed from the elements subtree. |
| PlatformSet | |
| PropertyChanged |
Raised when a property has changed. (Inherited from BindableObject) |
| PropertyChanging |
Raised when a property is about to change. (Inherited from BindableObject) |
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. |
| INameScope.RegisterName(String, Object) |
For internal use only. |
Extension Methods
| GetPropertyIfSet<T>(BindableObject, BindableProperty, T) | |
| SetAppThemeColor(BindableObject, BindableProperty, Color, Color) | |
| SetBinding(BindableObject, BindableProperty, String, BindingMode, IValueConverter, String) |
Creates and applies a binding to a property. |
| SetBinding<TSource>(BindableObject, BindableProperty, Expression<Func<TSource,Object>>, BindingMode, IValueConverter, String) |
Obsolete.
Creates and applies a binding from an expression. |
| SetOnAppTheme<T>(BindableObject, BindableProperty, T, T) | |
| FindByName<T>(Element, String) |
Returns the instance of type |