Flex简单文件上传

FileReferenceExample.as:



package oreilly.cookbook{

import flash.display.Sprite;

import flash.events.*;

import flash.net.FileFilter;

import flash.net.FileReference;

import flash.net.URLRequest;

import mx.controls.Button;

import mx.containers.Canvas;

public class FileReferenceExample extends Canvas {

private var uploadURL:URLRequest;

private var file:FileReference;

private var button:Button;

public function FileReferenceExample() {

uploadURL = new URLRequest();

uploadURL.url = "http://localhost:3003/UploadTest.aspx";

file = new FileReference();

configureListeners(file);

}

protected function btnUpload_Click(event:MouseEvent):void{

file.browse(getTypes());

}

private function configureListeners(dispatcher:IEventDispatcher):void {

dispatcher.addEventListener(Event.CANCEL, cancelHandler);

dispatcher.addEventListener(Event.COMPLETE, completeHandler);

dispatcher.addEventListener(HTTPStatusEvent.HTTP_STATUS, httpStatusHandler);

dispatcher.addEventListener(IOErrorEvent.IO_ERROR, ioErrorHandler);

dispatcher.addEventListener(Event.OPEN, openHandler);

dispatcher.addEventListener(ProgressEvent.PROGRESS, progressHandler);

dispatcher.addEventListener(SecurityErrorEvent.SECURITY_ERROR, securityErrorHandler);

dispatcher.addEventListener(Event.SELECT, selectHandler);

}

private function getTypes():Array {

var allTypes:Array = new Array(getImageTypeFilter(), getTextTypeFilter());

return allTypes;

}

private function getImageTypeFilter():FileFilter {

return new FileFilter("Images (*.jpg, *.jpeg, *.gif, *.png)", "*.jpg;*.jpeg;*.gif;*.png");

}

private function getTextTypeFilter():FileFilter {

return new FileFilter("Text Files (*.txt, *.rtf)", "*.txt;*.rtf");

}

private function cancelHandler(event:Event):void {

trace("cancelHandler: " + event);

}

private function completeHandler(event:Event):void {

trace("completeHandler: " + event);

}

private function httpStatusHandler(event:HTTPStatusEvent):void {

trace("httpStatusHandler: " + event);

}

private function ioErrorHandler(event:IOErrorEvent):void {

trace("ioErrorHandler: " + event);

}

private function openHandler(event:Event):void {

trace("openHandler: " + event);

}

private function progressHandler(event:ProgressEvent):void {

var file:FileReference = FileReference(event.target);

trace("progressHandler name=" + file.name + " bytesLoaded=" + event.bytesLoaded + " bytesTotal=" + event.bytesTotal);

}

private function securityErrorHandler(event:SecurityErrorEvent):void {

trace("securityErrorHandler: " + event);

}

private function selectHandler(event:Event):void {

var file:FileReference = FileReference(event.target);

trace("selectHandler: name=" + file.name + " URL=" + uploadURL.url);

file.upload(uploadURL);

}

}

}

FileReferenceExample.mxml:



<?xml version="1.0" encoding="utf-8"?>

<cookbook:FileReferenceExample xmlns:cookbook="oreilly.cookbook.*" xmlns:mx="http://www.adobe.com/2006/mxml" width="347" height="208">

<mx:Button id=”btnUpload” label="Button" x="10" y="10" click="btnUpload_Click(event);"/>

</cookbook:FileReferenceExample>

这种codebehind模式在as脚本里是无法操纵mxml界面元素的.

需要在as脚本里操纵界面元素,不要使用这种继承关系,直接在mxml里引用as脚本<mx:Script source="FileReferenceExample_cb.as"/>