TriggerBase Class
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TriggerBase Class


Represents the base class for specifying a conditional value within a Style object.

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

[LocalizabilityAttribute(LocalizationCategory.None, Readability = Readability.Unreadable)]
public abstract class TriggerBase : DependencyObject


Gets the DependencyObjectType that wraps the CLR type of this instance. (Inherited from DependencyObject.)


Gets the Dispatcher this DispatcherObject is associated with. (Inherited from DispatcherObject.)


Gets a collection of TriggerAction objects to apply when the trigger object becomes active. This property does not apply to the EventTrigger class.


Gets a collection of TriggerAction objects to apply when the trigger object becomes inactive. This property does not apply to the EventTrigger class.


Gets a value that indicates whether this instance is currently sealed (read-only).(Inherited from DependencyObject.)


Determines whether the calling thread has access to this DispatcherObject.(Inherited from DispatcherObject.)


Clears the local value of a property. The property to be cleared is specified by a DependencyProperty identifier. (Inherited from DependencyObject.)


Clears the local value of a read-only property. The property to be cleared is specified by a DependencyPropertyKey. (Inherited from DependencyObject.)


Coerces the value of the specified . This is accomplished by invoking any CoerceValueCallback function specified in property metadata for the dependency property as it exists on the calling DependencyObject.(Inherited from DependencyObject.)GTMT


Determines whether a provided DependencyObject is equivalent to the current DependencyObject.(Inherited from DependencyObject.)


Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object.)


Gets a hash code for this DependencyObject.(Inherited from DependencyObject.)


Creates a specialized enumerator for determining which dependency properties have locally set values on this DependencyObject. (Inherited from DependencyObject.)


Gets the Type of the current instance.(Inherited from Object.)


Returns the current effective value of a on this instance of a DependencyObject. (Inherited from DependencyObject.)GTMT


Re-evaluates the effective value for the specified dependency property(Inherited from DependencyObject.)


Creates a shallow copy of the current Object.(Inherited from Object.)


Invoked whenever the effective value of any on this DependencyObject has been updated. The specific dependency property that changed is reported in the event data. (Inherited from DependencyObject.)GTMT


Returns the local value of a , if it exists. (Inherited from DependencyObject.)GTMT

System_CAPS_pubmethodSetCurrentValue(DependencyProperty, Object)

Sets the value of a without changing its value source. (Inherited from DependencyObject.)GTMT

System_CAPS_pubmethodSetValue(DependencyProperty, Object)

Sets the local value of a , specified by its dependency property identifier. (Inherited from DependencyObject.)GTMT

System_CAPS_pubmethodSetValue(DependencyPropertyKey, Object)

Sets the local value of a read-only , specified by the DependencyPropertyKey identifier of the dependency property. (Inherited from DependencyObject.)GTMT


Returns a value that indicates whether serialization processes should serialize the value for the provided .(Inherited from DependencyObject.)GTMT


Returns a string that represents the current object.(Inherited from Object.)


Enforces that the calling thread has access to this DispatcherObject.(Inherited from DispatcherObject.)

The WPF styling and templating model allows you to specify triggers within your Style, ControlTemplate, and DataTemplate. Essentially, TriggerBase is the base class for objects that allow you to apply changes when certain conditions (such as when a certain property value becomes true, or when an event occurs) are satisfied.

There are several different types of triggers: Trigger, MultiTrigger, EventTrigger, DataTrigger, and MultiDataTrigger.

The Trigger class is the simplest type of triggers. A Trigger object allows you to apply changes based on the value of a property. For example, the following example shows a named Style available to Button controls. The Style defines a Trigger element that changes the Foreground property of a button when the IsPressed property is true.

If you need to apply changes based on the state of multiple properties, you can use the MultiTrigger. For an example, see the MultiTrigger page.

The EventTrigger class allows you to apply changes when an event occurs. The following example contains two EventTrigger objects, one of which occurs when the mouse enters the element and the other occurs when the mouse leaves the element.

These are also the DataTrigger and the MultiDataTrigger classes. These are similar to Trigger and MultiTrigger except that they are for data-bound properties.

.NET Framework
Available since 3.0
Available since 2.0
Windows Phone Silverlight
Available since 7.0

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

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