程序包 java.beans

类 PropertyChangeEvent

java.lang.Object

java.util.EventObject

java.beans.PropertyChangeEvent

所有已实现的接口:

Serializable

直接已知子类:

IndexedPropertyChangeEvent

public class PropertyChangeEvent
extends EventObject

A "PropertyChange" event gets delivered whenever a bean changes a "bound" or "constrained" property. A PropertyChangeEvent object is sent as an argument to the PropertyChangeListener and VetoableChangeListener methods.

Normally PropertyChangeEvents are accompanied by the name and the old and new value of the changed property. If the new value is a primitive type (such as int or boolean) it must be wrapped as the corresponding java.lang.* Object type (such as Integer or Boolean).

Null values may be provided for the old and the new values if their true values are not known.

An event source may send a null object as the name to indicate that an arbitrary set of if its properties have changed. In this case the old and new values should also be null.

另请参阅:

序列化表格

字段概要

从类继承的字段 java.util.EventObject

source

构造器概要

构造器

构造器	说明
PropertyChangeEvent(Object source, String propertyName, Object oldValue, Object newValue)	Constructs a new PropertyChangeEvent.

方法概要

限定符和类型	方法	说明
Object	getNewValue()	Gets the new value for the property, expressed as an Object.
Object	getOldValue()	Gets the old value for the property, expressed as an Object.
Object	getPropagationId()	The "propagationId" field is reserved for future use.
String	getPropertyName()	Gets the programmatic name of the property that was changed.
void	setPropagationId(Object propagationId)	Sets the propagationId object for the event.
String	toString()	Returns a string representation of the object.

从类继承的方法 java.util.EventObject

getSource

从类继承的方法 java.lang.Object

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

构造器详细资料

PropertyChangeEvent

public PropertyChangeEvent(Object source,
                           String propertyName,
                           Object oldValue,
                           Object newValue)

Constructs a new PropertyChangeEvent.

参数:

source - the bean that fired the event

propertyName - the programmatic name of the property that was changed

oldValue - the old value of the property

newValue - the new value of the property

抛出:

IllegalArgumentException - if source is null

方法详细资料

getPropertyName

public String getPropertyName()

Gets the programmatic name of the property that was changed.

返回:

The programmatic name of the property that was changed. May be null if multiple properties have changed.

getNewValue

public Object getNewValue()

Gets the new value for the property, expressed as an Object.

返回:

The new value for the property, expressed as an Object. May be null if multiple properties have changed.

getOldValue

public Object getOldValue()

Gets the old value for the property, expressed as an Object.

返回:

The old value for the property, expressed as an Object. May be null if multiple properties have changed.

setPropagationId

public void setPropagationId(Object propagationId)

Sets the propagationId object for the event.

参数:

propagationId - The propagationId object for the event.

getPropagationId

public Object getPropagationId()

The "propagationId" field is reserved for future use. In Beans 1.0 the sole requirement is that if a listener catches a PropertyChangeEvent and then fires a PropertyChangeEvent of its own, then it should make sure that it propagates the propagationId field from its incoming event to its outgoing event.

返回:

the propagationId object associated with a bound/constrained property update.

toString

public String toString()

Returns a string representation of the object.

覆盖:

toString 在类中 EventObject

返回:

a string representation of the object

从以下版本开始:

1.7