程序包 ohos.data.rdb

类 DataObservable

java.lang.Object

ohos.data.rdb.DataObservable

public class DataObservable
extends Object

Represents a set of DataObserver objects that listen for changes of the observed objects.

从以下版本开始:

3

SystemCapability

SystemCapability.Data#DATA_APPDATAMGR

构造器概要

构造器

构造器	说明
DataObservable()

方法概要

限定符和类型	方法	说明
void	add(DataObserver dataObserver)	Adds an observer to the observer set.
void	notifyObservers()	Sends a notification to all the observers in the observer set.
void	remove(DataObserver dataObserver)	Removes a specified observer from the observer set.
void	removeAll()	Removes all observers from the observer set.

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

DataObservable

public DataObservable()

方法详细资料

add

public void add(DataObserver dataObserver)

Adds an observer to the observer set. If the observer already exists in the observer set, it will not be added.

参数:

dataObserver - data observer.

remove

public void remove(DataObserver dataObserver)

Removes a specified observer from the observer set.

参数:

dataObserver - data observer.

notifyObservers

public void notifyObservers()

Sends a notification to all the observers in the observer set.

removeAll

public void removeAll()

Removes all observers from the observer set.