DataTrigger Class

Reference

Definition

Namespace:: Microsoft.Maui.Controls

Assembly:: Microsoft.Maui.Controls.dll

Source:: DataTrigger.cs

Source:: DataTrigger.cs

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Class that represents a condition on an arbitrary binding, along with a list of Setter objects that will be applied when the condition is met.

public ref class DataTrigger sealed : Microsoft::Maui::Controls::TriggerBase, Microsoft::Maui::Controls::Xaml::IValueProvider

[Microsoft.Maui.Controls.ContentProperty("Setters")]
[Microsoft.Maui.Controls.Xaml.AcceptEmptyServiceProvider]
public sealed class DataTrigger : Microsoft.Maui.Controls.TriggerBase, Microsoft.Maui.Controls.Xaml.IValueProvider

[<Microsoft.Maui.Controls.ContentProperty("Setters")>]
[<Microsoft.Maui.Controls.Xaml.AcceptEmptyServiceProvider>]
type DataTrigger = class
    inherit TriggerBase
    interface IValueProvider

Public NotInheritable Class DataTrigger
Inherits TriggerBase
Implements IValueProvider

Inheritance: Object

BindableObject

TriggerBase
DataTrigger

Attributes: ContentPropertyAttribute AcceptEmptyServiceProviderAttribute

Implements: IValueProvider

Remarks

The DataTrigger class is suitable for checking values on other controls, as well as any property on the control to which it has been added. That is, its default binding context is the control to which it has been added.

The XML example below prompts the user to type in the secret, which is, "The text color is green". When the user has typed "The", the Entry text changes color to red. When the user completes the secret, the Label text turns green. The code is turned back to the default color if the user then edits the secret. This example shows how to bind to the enclosing control (Entry from Entry), and to an arbitary control (Entry from Label)

<?xml version="1.0" encoding="utf-8"?>
<ContentPage    xmlns="http://xamarin.com/schemas/2014/forms"
                xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
                xmlns:local="clr-namespace:TriggerDemo"
                x:Class="TriggerDemo.TriggerDemoPage">
<StackLayout VerticalOptions="Center">
<Label Text="Can you tell me the secret?" VerticalOptions="Center" HorizontalOptions="Center">
<Label.Triggers>
<DataTrigger TargetType="Label"
                    Binding="{Binding Source={x:Reference checkEntry},
                                      Path=Text}"
                    Value="The text color is green">
<Setter Property="TextColor" Value="Color.Green" />
</DataTrigger>
</Label.Triggers>
</Label>
<Entry Placeholder="Type the secret here." x:Name="checkEntry" VerticalOptions="Center" HorizontalOptions="Center">
<Entry.Triggers>
<DataTrigger TargetType="Entry"
                    Binding="{Binding Text}"
                    Value="The">
<Setter Property="TextColor" Value="Red" />
</DataTrigger>
</Entry.Triggers>
</Entry>
</StackLayout>
</ContentPage>

Constructors

DataTrigger(Type)

Initializes a new DataTrigger instance.

Properties

Binding	Gets or sets the binding whose value will be compared to Value to determine when to invoke the setters.
BindingContext	Gets or sets an object that contains the properties that will be targeted by the bound properties that belong to this BindableObject. This is a bindable property. (Inherited from BindableObject)
Dispatcher	Gets the dispatcher that was available when this bindable object was created, otherwise tries to find the nearest available dispatcher (probably the window's/app's). (Inherited from BindableObject)
EnterActions	Gets the list of TriggerAction objects that will be invoked when the trigger condition is met. Ignored for the EventTrigger class. (Inherited from TriggerBase)
ExitActions	Gets the list of TriggerAction objects that will be invoked after the trigger condition is no longer met. Ignored for the EventTrigger class. (Inherited from TriggerBase)
IsSealed	Gets a value that indicates whether or not the trigger is sealed. (Inherited from TriggerBase)
Setters	Gets the list of Setter objects that will be applied when the binding that is named by the Binding property becomes equal to Value.
TargetType	The type of object to which this TriggerBase object can be attached. (Inherited from TriggerBase)
Value	Gets or sets the value of the binding, named by the Binding property, that will cause the setters to be applied.

Methods

ApplyBindings()	Applies all the current bindings to BindingContext. (Inherited from BindableObject)
ClearValue(BindableProperty)	Clears any value that is previously set for a bindable property. (Inherited from BindableObject)
ClearValue(BindablePropertyKey)	Clears any value that is previously set for a bindable property, identified by its key. (Inherited from BindableObject)
CoerceValue(BindableProperty)	Coerces the value of the specified bindable property. This is done by invoking BindableProperty.CoerceValueDelegate of the specified bindable property. (Inherited from BindableObject)
CoerceValue(BindablePropertyKey)	Coerces the value of the specified bindable property. This is done by invoking BindableProperty.CoerceValueDelegate of the specified bindable property. (Inherited from BindableObject)
GetValue(BindableProperty)	Returns the value that is contained in the given bindable property. (Inherited from BindableObject)
IsSet(BindableProperty)	Determines whether or not a bindable property exists and has a value set. (Inherited from BindableObject)
OnBindingContextChanged()	Raises the BindingContextChanged event. (Inherited from BindableObject)
OnPropertyChanged(String)	Raises the PropertyChanged event. (Inherited from BindableObject)
OnPropertyChanging(String)	Raises the PropertyChanging event. (Inherited from BindableObject)
RemoveBinding(BindableProperty)	Removes a previously set binding from a bindable property. (Inherited from BindableObject)
SetBinding(BindableProperty, BindingBase)	Assigns a binding to a bindable property. (Inherited from BindableObject)
SetValue(BindableProperty, Object)	Sets the value of the specified bindable property. (Inherited from BindableObject)
SetValue(BindablePropertyKey, Object)	Sets the value of the specified bindable property. (Inherited from BindableObject)
UnapplyBindings()	Removes all current bindings from the current context. (Inherited from BindableObject)

Events

BindingContextChanged	Occurs when the value of the BindingContext property changes. (Inherited from BindableObject)
PropertyChanged	Occurs when a property value changes. (Inherited from BindableObject)
PropertyChanging	Occurs when a property value is changing. (Inherited from BindableObject)

Explicit Interface Implementations

IDynamicResourceHandler.SetDynamicResource(BindableProperty, String)	(Inherited from BindableObject)
IValueProvider.ProvideValue(IServiceProvider)

Extension Methods

GetPropertyIfSet<T>(BindableObject, BindableProperty, T)
SetAppTheme<T>(BindableObject, BindableProperty, T, T)
SetAppThemeColor(BindableObject, BindableProperty, Color, Color)
SetBinding(BindableObject, BindableProperty, String, BindingMode, IValueConverter, String)	Creates and applies a binding to a property.
SetBinding<TSource,TProperty>(BindableObject, BindableProperty, Func<TSource,TProperty>, BindingMode, IValueConverter, Object, String, Object, Object, Object)	Creates a binding between a property on the source object and a property on the target object.

Applies to

Share via