程序包 ohos.aafwk.abilityjet.activedata

类 DataObserver<T>

java.lang.Object

ohos.aafwk.abilityjet.activedata.DataObserver<T>

类型参数:

T - Indicates the type of data to observe.

public abstract class DataObserver<T>
extends Object

A base class of observers that receive notifications upon data changes of ActiveData.

Observers of ActiveData must inherit this class and override the onChanged(java.lang.Object) method. In this way, ActiveData can notify observers of data changes by using onChanged(java.lang.Object).

DataObserver holds a Lifecycle object by using the setLifecycle(ohos.aafwk.ability.Lifecycle) method. The object indicates the lifecycle of the matching Ability or AbilitySlice. DataObserver also allows ActiveData to observe its lifecycle changes. Therefore, DataObserver and ActiveData observe each other. DataObserver observes data changes of ActiveData, and ActiveData observes lifecycle changes of DataObserver.

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SystemCapability

SystemCapability.Aafwk#ABILITYJET

构造器概要

构造器

构造器	说明
DataObserver()

方法概要

限定符和类型	方法	说明
abstract void	onChanged(T value)	Notifies an observer that the data being observed has changed.
void	setLifecycle(Lifecycle owner)	Sets the lifecycle state of an observer.

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

构造器详细资料

DataObserver

public DataObserver()

方法详细资料

onChanged

public abstract void onChanged(T value)

Notifies an observer that the data being observed has changed.

Observers of ActiveData must implement this method so that they can be notified upon data changes.

参数:

value - Indicates the new value of the data being observed. This parameter cannot be null.

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setLifecycle

public final void setLifecycle(Lifecycle owner)

Sets the lifecycle state of an observer.

The ActiveData object will be notified when the lifecycle state of an observer changes.

参数:

owner - Indicates the lifecycle state of the observer. This parameter cannot be null.

抛出:

IllegalArgumentException - invalid parameter

IllegalStateException - invalid lifeOwner

从以下版本开始:

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