实现AIR应用自动更新的大致原理(冰山上的播客)

实现AIR应用自动更新的大致原理，以下是类文件和调用示例：

package Neo
{
        import flash.display.*;
        import flash.filesystem.*;
        import flash.desktop.Updater;
        import flash.events.*;
        import flash.net.*;
        import flash.xml.*;
        import flash.text.TextField;
        import flash.utils.ByteArray;
        import flash.events.IOErrorEvent;

        public class AIRUpdater extends Sprite
        {
                public var version:String;
                public var updataURL:String;
               
                private var updataRequest:URLRequest;
                private var updataLoader=new URLLoader();
                private var newVersion:String;
                private var airURLString:String;
                private var urlReq:URLRequest;
                private var urlStream:URLStream;
                private var fileData:ByteArray;
                private var baseSprite:Sprite=new Sprite();
                private var tipText:TextField=new TextField();
                private var btYes:Sprite=new Sprite();
                private var btYesText:TextField=new TextField();
                private var btNo:Sprite=new Sprite();
                private var btNoText:TextField=new TextField();

                public function AIRUpdater():void
                {
                        baseSprite.graphics.beginFill(0×000000,0.5);
                        baseSprite.graphics.lineStyle(8,0×000000,0.1);
                        baseSprite.graphics.drawRoundRect(0,0,360,160,10);
                        baseSprite.graphics.endFill();
                        /*add base*/
                        tipText.width=300;
                        tipText.height=30;
                        tipText.x=tipText.y=30;
                        tipText.autoSize=”center”;
                        tipText.textColor=0xFFFFFF;
                        tipText.text=”You must update your AIR Application now,ok?”;
                        baseSprite.addChild(tipText);
                        /*add button*/
                        btYes.graphics.beginFill(0×000000,0.5);
                        btYes.graphics.lineStyle(1,0×000000,0.1);
                        btYes.graphics.drawRoundRect(0,0,36,20,10);
                        btYes.graphics.endFill();
                        btYesText.width=36;
                        btYesText.text=”Yes”;
                        btYesText.autoSize=”center”;
                        btYesText.textColor=0xFFFFFF;
                        btYes.addChild(btYesText);
                        btNo.graphics.beginFill(0×000000,0.5);
                        btNo.graphics.lineStyle(1,0×000000,0.1);
                        btNo.graphics.drawRoundRect(0,0,36,20,10);
                        btNo.graphics.endFill();
                        btNoText.width=36;
                        btNoText.text=”No”;
                        btNoText.autoSize=”center”;
                        btNoText.textColor=0xFFFFFF;
                        btNoText.selectable=btYesText.selectable=false;
                        btNo.addChild(btNoText);
                        btYes.x=100;
                        btYes.y=100;
                        btNo.x=210;
                        btNo.y=100;
                        btYes.buttonMode=btNo.buttonMode=true;
                        baseSprite.addChild(btYes);
                        baseSprite.addChild(btNo);
                }
                /*Function For Update Application*/
                public function updateMyApp():void
                {
                        updataRequest=new URLRequest(updataURL);
                        updataLoader.load(updataRequest);
                        updataLoader.addEventListener(IOErrorEvent.IO_ERROR,errorHandler);
                        updataLoader.addEventListener(Event.COMPLETE,loaderCompleteHandler);
                }
                /*loaderCompleteHandler*/
                private function loaderCompleteHandler(event:Event):void
                {
                        try {
                                var result:XML=new XML(updataLoader.data);
                                if (version != result.version)
                                {
                                        newVersion=result.version;
                                        airURLString=result.lastpublic;
                                        trace(”马上更新到最新版吗？” + “有新的更新”);
                                        addChild(baseSprite);
                                        baseSprite.x=(stage.stageWidth-baseSprite.width)/2;
                                        baseSprite.y=(stage.stageHeight-baseSprite.height)/2;
                                        btYes.addEventListener(MouseEvent.CLICK,updateBtHandler);
                                        btNo.addEventListener(MouseEvent.CLICK,removeBtHandler);
                                }
                        } catch (e:TypeError) {
                                trace(”Updata Application Error:Could not parse the XML file.”);
                        }
                }
                /*errorHandler*/
                private function errorHandler(e:IOErrorEvent):void
                {
                        trace(”Updata Application Error:Had problem loading the XML File.”);
                }
                private function updateBtHandler(event:MouseEvent):void
                {
                        urlReq=new URLRequest(airURLString);
                        urlStream=new URLStream  ;
                        fileData=new ByteArray  ;
                        urlStream.addEventListener(Event.COMPLETE,loaded);
                        urlStream.load(urlReq);
                }
                private function removeBtHandler(event:MouseEvent):void
                {
                        removeChild(baseSprite);
                }
                private function loaded(event:Event):void
                {
                        urlStream.readBytes(fileData,0,urlStream.bytesAvailable);
                        writeAirFile();
                }
                private function writeAirFile():void
                {
                        var file:File=File.desktopDirectory.resolvePath(”lastPublish.air”);
                        var fileStream:FileStream=new FileStream  ;
                        fileStream.addEventListener(Event.CLOSE,fileClosed);
                        fileStream.openAsync(file,FileMode.WRITE);
                        fileStream.writeBytes(fileData,0,fileData.length);
                        fileStream.close();
                }
                private function fileClosed(event:Event):void
                {
                        trace(”The AIR file is written.”);
                        var updater:Updater=new Updater  ;
                        var airFile:File=File.desktopDirectory.resolvePath(”lastPublish.air”);
                        updater.update(airFile,newVersion);
                }
        }
}

调用示例：
import flash.display.*;
import flash.filesystem.*;
import flash.desktop.Updater;
import flash.events.*;
import flash.net.*;
import flash.xml.*;
import flash.utils.ByteArray;
import flash.events.IOErrorEvent;
import Neo.AIRUpdater;

var aupSample:AIRUpdater=new AIRUpdater();
aupSample.version=”alpha1″;
aupSample.updataURL=”http://localhost/testUpdate/version.xml”;
aupSample.updateMyApp();
addChild(aupSample);
用于判断版本的XML结构示意：
<?xml version=”1.0″ encoding=”utf-8″?>
<example>
<version>alpha2</version>
<lastpublic>http://localhost/testUpdate/main.air</lastpublic>
</example>