mx.events.PropertyChangeEvent

sinkingboat

1.簡(jiǎn)介
       繼承關(guān)系：PropertyChangeEvent Event Object
       如果對(duì)象的屬性值發(fā)生變化，可以派發(fā)PropertyChangeEvent事件來(lái)表示。
       Flex 數(shù)據(jù)綁定機(jī)制也使用此事件。
       例子請(qǐng)參考《PropertyChangeEvent事件》

2.常見(jiàn)屬性和方法
2.1 屬性PROPERTY_CHANGE
PROPERTY_CHANGE : String = "propertyChange"
[靜態(tài)] PropertyChangeEvent.PROPERTY_CHANGE 常量可為 PropertyChange 事件定義事件對(duì)象的 type 屬性的值。

2.2 屬性kind
指定更改的類(lèi)型。String類(lèi)型
可能的值為 PropertyChangeEventKind.UPDATE、PropertyChangeEventKind.DELETE 和 null

2.3 屬性newValue
更改后的屬性的值。Object類(lèi)型

2.4 屬性oldValue
更改前的屬性的值。Object類(lèi)型

2.5 屬性property
需要更改的屬性。Object類(lèi)型

2.6 屬性source
發(fā)生更改屬性的對(duì)象。Object類(lèi)型

2.7 屬性currentTarget
用于定義處理該事件的事件偵聽(tīng)器的 Object。Object類(lèi)型
例如，如果您使用myButton.addEventListener() 注冊(cè)某個(gè)事件偵聽(tīng)器，則 myButton 為 currentTarget 的值。

2.8 屬性target
事件目標(biāo)。Object類(lèi)型
派發(fā)事件的 Object；它不一定是偵聽(tīng)該事件的 Object。使用 currentTarget 屬性始終可以訪問(wèn)偵聽(tīng)事件的 Object。


3.源代碼

1. package mx.events
   
2. {
   
3. 
   
4. import flash.events.Event;
   
5. import mx.events.PropertyChangeEventKind;
6. 
   
7. public class PropertyChangeEvent extends Event
   
8. {
   
9.     include "../core/Version.as";
   
10. 
    
11.     //類(lèi)屬性
12.     public static const PROPERTY_CHANGE:String = "propertyChange";
13. 
    

      //類(lèi)方法

1.     public static function createUpdateEvent(
   
2.                                     source:Object,
   
3.                                     property:Object,
   
4.                                     oldValue:Object,
   
5.                                     newValue:Object):PropertyChangeEvent
   
6.     {
   
7.         var event:PropertyChangeEvent =
   
8.             new PropertyChangeEvent(PROPERTY_CHANGE);
   
9.         
   
10.         event.kind = PropertyChangeEventKind.UPDATE;
    
11.         event.oldValue = oldValue;
    
12.         event.newValue = newValue;
    
13.         event.source = source;
    
14.         event.property = property;
    
15.         
    
16.         return event;
    
17.     }
    
18. 
    
19.     // 構(gòu)造函數(shù)
    
20.     public function PropertyChangeEvent(type:String, bubbles:Boolean = false,
    
21.                                         cancelable:Boolean = false,
    
22.                                         kind:String = null,
    
23.                                         property:Object = null,
    
24.                                         oldValue:Object = null,
    
25.                                         newValue:Object = null,
    
26.                                         source:Object = null)
    
27.     {
    
28.         super(type, bubbles, cancelable);
    
29. 
    
30.         this.kind = kind;
    
31.         this.property = property;
    
32.         this.oldValue = oldValue;
    
33.         this.newValue = newValue;
    
34.         this.source = source;
    
35.     }
    
36. 
    
37.     // 屬性kind
    
38.     public var kind:String;
    
39. 
    
40.  
    
41.     // 屬性newValue
    
42.     public var newValue:Object;
    
43. 
    
44. 
    
45.     // 屬性 oldValue
    
46.     public var oldValue:Object;
    
47. 
    
48. 
    
49.     // 屬性property
    
50.     public var property:Object;
    
51. 
    
52.     // 屬性source
    
53.     public var source:Object;
    
54. 
    
55.     //方法clone，繼承自Event
    
56.     /**
    
57.      * @private
    
58.      */
    
59.     override public function clone():Event
    
60.     {
    
61.         return new PropertyChangeEvent(type, bubbles, cancelable, kind,
    
62.                                        property, oldValue, newValue, source);
    
63.     }
    
64. }
    
65. 
    
66. }

參考文獻(xiàn)
1.類(lèi)參考.http://help.adobe.com/zh_CN/FlashPlatform/reference/actionscript/3/mx/events/PropertyChangeEvent.html?filter_flex=4.1&filter_flashplayer=10.2&filter_air=2.6#kind
2.源代碼.http://opensource.adobe.com/svn/opensource/flex/sdk/trunk/frameworks/projects/framework/src/mx/events/PropertyChangeEvent.as