MACROMEDIA FLEX 2-MIGRATING APPLICATIONS TO FLEX 2 Manuel d'utilisateur télécharger pdf (Page 107)

Binding from a property 107

The Flex compiler automatically generates an event named propertyChange for all public

properties so the properties can be used as the source of a data binding expression. In this case,

specifying the

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

[Bindable(event="propertyChange")]

Binding from a single property

To make a single property usable as the source for a data binding expression, add the

[Bindable] metadata tag before the property declaration. The property can be public,

protected, or private.

Flex 1.5:

var foo:String; // You could bind to this in 1.5

Flex 2:

[Bindable]

public var foo:String;

The Flex compiler automatically generates an event named propertyChange for all public

properties so the properties can be used as the source of a data binding expression. In this case,

specifying the

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

[Bindable(event="propertyChange")]

Binding from a property defined by a setter and getter

method

In Flex 1.5, you used the [ChangeEvent] metadata tag on setter/getter pairs. In Flex 2, you

replace the

[ChangeEvent] metadata tag with the [Bindable] metadata tag and dispatch the

event in the method. This strategy also applies to other methods that dispatched custom

events.

Flex 1.5:

[ChangeEvent("maxFontSizeChanged")]

// Define public getter method.

public function get maxFontSize():Number {

return _maxFontSize;

}

Flex 2:

[Bindable(event="maxFontSizeChanged")]

// Define public getter method.

public function get maxFontSize():Number {

return _maxFontSize;

}

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MACROMEDIA FLEX 2-MIGRATING APPLICATIONS TO FLEX 2 Manuel d'utilisateur Page 107