MACROMEDIA FLEX 2-MIGRATING APPLICATIONS TO FLEX 2 Manuale Utente Scaricare il pdf (Pagina 108)

108 Binding

The following is a Flex 2 example of a getter/setter pair that uses the [Bindable] metadata

tag:

// Define private variable.

private var _maxFontSize:Number = 15;

[Bindable(event="maxFontSizeChanged")]

// Define public getter method.

public function get maxFontSize():Number {

return _maxFontSize;

}

// Define public setter method.

public function set maxFontSize(value:Number):void {

if (value <= 30) {

_maxFontSize = value;

} else _maxFontSize = 30;

// Create event object.

var eventObj:Event = new Event("maxFontSizeChanged");

dispatchEvent(eventObj);

}

You can omit the event name in the metadata tag, as the following example shows:

// Define private variable.

private var _maxFontSize:Number = 15;

[Bindable]

// Define public getter method.

public function get maxFontSize():Number {

return _maxFontSize;

}

// Define public setter method.

public function set maxFontSize(value:Number):void {

if (value <= 30) {

_maxFontSize = value;

} else _maxFontSize = 30;

}

The Flex compiler automatically generates an event named propertyChange. In this case,

specifying the

[Bindable] metadata tag with no event is the same as specifying the following:

[Bindable(event="propertyChange")]

1 2 ... 103 104 105 106 107 108 109 110 111 112 113 ... 183 184

Nessun commento

MACROMEDIA FLEX 2-MIGRATING APPLICATIONS TO FLEX 2 Manuale Utente Pagina 108