Flex callback Function Application Example _flex

A callback function is a function called by a function pointer. If you pass the pointer (address) of a function to another function as an argument, when the pointer is used to call the function it points to, we say this is a callback function. The callback function is not called directly by the implementation method of the function, but is called by another method when a particular event or condition occurs, and is used to correspond to the event or condition.

Below or through the way of the Code, to implement a callback function application.

Flexcallback.mxml

Copy Code code as follows:

<?xml version= "1.0" encoding= "Utf-8"?>
<s:application xmlns:fx= "http://ns.adobe.com/mxml/2009"
Xmlns:s= "Library://ns.adobe.com/flex/spark"
xmlns:mx= "Library://ns.adobe.com/flex/mx" width= "100%" height= "100%" >

<fx:Script>
<! [cdata[

Import Flash.external.ExternalInterface;
Import flash.system.Security;
Import Mx.controls.Alert;
Import mx.events.FlexEvent;
public var callbackinfo:string = "";

Public Function Dosend (): void{

var Call:flexapp = new Flexapp ("Hello", callBack);

}

Public function CallBack (info): void{

Alert.show (info);

}

]]>
</fx:Script>

<fx:Declarations>
<!--place non-visual elements (such as services, value objects) here-->
</fx:Declarations>
<s:panel width= "100%" height= "100%" >

<s:button label= "Send" click= "Dosend ()" >

</s:Button>


</s:Panel>

</s:Application>

Flexapp class of your own definition

Copy Code code as follows:

Package
{
public class Flexapp
{

Public Function Flexapp (param:string,func:function)
{

Func.call (NULL, "received");
}
}
}