纯AS代码实现可预览本地图片的flash上传客户端(AS3)

需要Flash Player 10+版本的支持，原理就是主要利用fp10中的FileReference.load()，FileReference.data和Loader.loadBytes()三个方法通过图片加载到内存中，来实现预览本地图片，但这个方式不太适用大图片预览，
    需要Flash Player 10+版本的支持，原理就是主要利用fp10中的FileReference.load()，FileReference.data和Loader.loadBytes()三个方法通过图片加载到内存中，来实现预览本地图片，但这个方式不太适用大图片预览，图片越大内存消耗就越大。

 

[注意]

1.我这边图片上传路径是无效的，所以图片上传失败是正常的，你们可以改一下上传路径即可；

2.需要Flash Player 10的支持；

3.这次主要研究是预览本地图片功能。

package project.test
{
import flash.display.*;
import flash.geom.Rectangle;
import flash.net.*;
import flash.text.*;
import flash.filters.*;
import flash.events.*;
import flash.system.Security;

import fl.controls.Button;
import fl.controls.ProgressBar;
import fl.controls.ProgressBarMode;

/**
* @link [e-mail]
* @author Kinglong
* @playerversion fp10
*/
[SWF(width="500", height="300", frameRate="24", backgroundColor="#FFFFFF")]
public class TestUpload extends Sprite {
 
   private const DEFAULT_UPLOAD_PAGE:String = "http://test.klstudio.com/upload.asp"; 
   private const BOX_WIDTH:uint = 500;
   private const BOX_HEIGHT:uint = 300;
 
   private const STATE_CACHE:String = "cache";
   private const STATE_UPLOAD:String = "upload";
 
   private var _filters:Array;
   private var _file:FileReference;
   private var _loader:Loader;
   private var _progress:ProgressBar;
   private var _state:String;
   private var _buttons:Array;
   private var _labels:Array;
   private var _txts:Array;
   private var _rect:Rectangle;
   private var _state_txt:TextField;
 
   public function TestUpload() {
    Security.allowDomain("*");
  
    _buttons = [];
    _txts = [];
    _labels = ["文件名称:","文件类型:","文件大小:","修改时间:"];
  
    _rect = new Rectangle(20, 80, 180, 180);
    _state = STATE_CACHE;
  
    //背景;
    this.graphics.beginFill(0x333333);
    this.graphics.drawRoundRect(0, 0, BOX_WIDTH, BOX_HEIGHT, 10, 10);
    this.graphics.endFill();
    this.graphics.beginFill(0xEFEFEF);
    this.graphics.drawRoundRect(1, 1, BOX_WIDTH - 2, BOX_HEIGHT - 2, 10, 10);
    this.graphics.endFill();
    this.graphics.beginFill(0x666666);
    this.graphics.drawRoundRect(10, 30, BOX_WIDTH - 20, BOX_HEIGHT - 60, 20, 20);  
    this.graphics.endFill();
    this.graphics.beginFill(0xFEFEFE);
    this.graphics.drawRoundRect(11, 31, BOX_WIDTH - 22, BOX_HEIGHT - 62, 20, 20);
    this.graphics.endFill();
  
    this.graphics.beginFill(0xCCCCCC);
    this.graphics.drawRect(11, 70, BOX_WIDTH - 22, 1);
    this.graphics.endFill();
  
    this.graphics.beginFill(0x000000);
    this.graphics.drawRect(_rect.x-1, _rect.y-1, _rect.width+2, _rect.height+2);
    this.graphics.endFill();  
    this.graphics.beginFill(0xEEEEEE);
    this.graphics.drawRect(_rect.x, _rect.y, _rect.width, _rect.height);
    this.graphics.endFill();
  
  
    //标题;
    var label:TextField;  
    label = getLabel("图片上传（预览图片版） by Kinglong", getTextFormat(0xFFFFFF, 14, true));
    label.x = 10;
    label.y = 5;
    label.filters = [getLabelFilter(0x000000)];
    this.addChild(label);
  
    for (var i:uint = 0; i < _labels.length; i++ ) {  
     label = getLabel(_labels[i], getTextFormat(0x333333, 12), false, false);   
     label.x = _rect.right+5;
     label.y = _rect.y + 25 * i;
     label.width = 280;
     label.height = 20;
     _txts.push(label);
     this.addChild(label);
    }  
  
    _state_txt = getLabel("状态:", getTextFormat(0x333333, 12));
    _state_txt.x = 10;
    _state_txt.y = BOX_HEIGHT - _state_txt.height - 5;
    this.addChild(_state_txt);
  
    //按钮;
    var button:Button;
    button = getButton("选择文件", 80);  
    button.move(20, 40);
  
    button = getButton("上传文件", 80);  
    button.move(105, 40);
    button.enabled = false;
  
    //进度条;
    _progress = new ProgressBar();
    _progress.move(190, 40);
    _progress.setSize(290,22);
    _progress.mode = ProgressBarMode.MANUAL;     
    this.addChild(_progress);
  
    //文件类型;
    _filters = [];
    var filter:FileFilter;  
    filter = new FileFilter("所有支持图片文件(*.jpg,*.jpeg,*.gif,*.png)", "*.jpg;*.jpeg;*.gif;*.png");
    _filters[_filters.length] = filter;
    filter = new FileFilter("JPEG files(*.jpg,*.jpeg)","*.jpg;*.jpeg");
    _filters[_filters.length] = filter;
    filter = new FileFilter("GIF files (*.gif)","*.gif");
    _filters[_filters.length] = filter;
    filter = new FileFilter("PNG files(*.png)","*.png");
    _filters[_filters.length] = filter;
  
    _file = new FileReference();
    _file.addEventListener(Event.COMPLETE, fileHandler);
    _file.addEventListener(DataEvent.UPLOAD_COMPLETE_DATA, fileHandler);
    _file.addEventListener(Event.SELECT, fileHandler);
    _file.addEventListener(Event.OPEN, fileHandler);  
    _file.addEventListener(ProgressEvent.PROGRESS, fileHandler);
    _file.addEventListener(SecurityErrorEvent.SECURITY_ERROR, fileHandler);
    _file.addEventListener(IOErrorEvent.IO_ERROR, fileHandler);
    _file.addEventListener(HTTPStatusEvent.HTTP_STATUS, fileHandler);
  
    _loader = new Loader();
    _loader.contentLoaderInfo.addEventListener(Event.COMPLETE, loadHandler);
    this.addChild(_loader);
   }
 
   public function get state():String {
    return _state;
   }
 
   private function clickHandler(event:MouseEvent):void {
    switch(event.target) {
     case _buttons[0]:
      _file.browse(_filters);
      break;
     case _buttons[1]:
      _file.upload(new URLRequest(DEFAULT_UPLOAD_PAGE));
      _state = STATE_UPLOAD;    
      _buttons[0].enabled = false;
      _buttons[1].enabled = false;
      break;
    }
   }
 
   private function loadHandler(event:Event):void {
    _loader.scaleX = _loader.scaleY = 1;
    var w:uint = _loader.width;
    var h:uint = _loader.height;
    if (w > _rect.width || h > _rect.height) {   
     var ip:Number = w / h;
     var lp:Number = _rect.width / _rect.height;  
     _loader.width = (ip > lp)?_rect.width:_rect.height*ip;
     _loader.height = (ip > lp)?_rect.width / ip:_rect.height;
    }
    _loader.x = _rect.x + (_rect.width - _loader.width) / 2;
    _loader.y = _rect.y + (_rect.height - _loader.height) / 2;  
    _loader.visible = true;
   }
 
   private function fileHandler(event:Event):void {
    switch(event.type) {
     case Event.COMPLETE:
      if(state == STATE_CACHE){
       _loader.loadBytes(_file.data);
      }
      break;
     case DataEvent.UPLOAD_COMPLETE_DATA:
      debug("图片上传完成!");
      _buttons[0].enabled = true;
      _buttons[1].enabled = false;
      _progress.setProgress(0, 1);
      break;
     case Event.SELECT:
      _txts[0].text = _labels[0] + _file.name;
      _txts[1].text = _labels[1] + _file.type;
      _txts[2].text = _labels[2] + ((_file.size > 1024 * 1024)?Math.round(_file.size * 10 / (1024*1024))/10 + "MB":Math.round(_file.size * 10 / 1024)/10 + "KB");    
      _txts[3].text = _labels[3] + date2str(_file.modificationDate);
      _buttons[0].enabled = true;
      _buttons[1].enabled = true;
      _file.load();
      _state = STATE_CACHE;
      _loader.visible = false;
      debug("图片已经准备!");
      break;
     case Event.OPEN:
      if(state == STATE_UPLOAD){
       debug("正在上传图片...");
      }
      break;
     case ProgressEvent.PROGRESS:
      if (state == STATE_UPLOAD) {
       var pEvent:ProgressEvent = event as ProgressEvent;
       _progress.setProgress(pEvent.bytesLoaded, pEvent.bytesTotal);
      }
      break;
     case SecurityErrorEvent.SECURITY_ERROR:
     case IOErrorEvent.IO_ERROR:
     case HTTPStatusEvent.HTTP_STATUS:    
      if (state == STATE_UPLOAD) {
       debug("图片上传失败!");
       _buttons[0].enabled = true;
       _buttons[1].enabled = true;
      }else {
       debug("图片缓冲失败!");
      }
      _progress.setProgress(0, 1);
      break;
   
    }
   }
 
   private function getButton(lbl:String,width:uint=120):Button {
    var button:Button = new Button();
    button.label = lbl;
    button.setSize(width, 22);
    button.setStyle("textFormat", getTextFormat());
    button.setStyle("disabledTextFormat", getTextFormat(0x999999));
    button.setStyle("textPadding",4);
    button.addEventListener(MouseEvent.CLICK, clickHandler);  
    this.addChild(button);
    _buttons.push(button);
    return button;
   }
 
   private function getLabel(label:String, format:TextFormat, selectable:Boolean = false, autoSize:Boolean = true):TextField {  
    var lbl:TextField = new TextField();
    lbl.selectable = selectable;
    lbl.defaultTextFormat = format;
    if(autoSize){
     lbl.autoSize = TextFieldAutoSize.LEFT;
    }
    lbl.text = label;
    return lbl;
   }
 
   private function getTextFormat(color:uint=0x000000,size:uint = 12,bold:Boolean=false):TextFormat {
    var format:TextFormat = new TextFormat();
    format.font = "宋体";
    format.color = color;
    format.size = size;
    format.bold = bold;
    return format;
   }
 
   private function getLabelFilter(color:uint=0xFFFFFF):BitmapFilter {
            var alpha:Number = 0.8;
            var blurX:Number = 2;
            var blurY:Number = 2;
            var strength:Number = 3;
            var inner:Boolean = false;
            var knockout:Boolean = false;
            var quality:Number = BitmapFilterQuality.HIGH;
            return new GlowFilter(color,
                                  alpha,
                                  blurX,
                                  blurY,
                                  strength,
                                  quality,
                                  inner,
                                  knockout);
   }
 
   private function date2str(day:Date):String {
    var str:String = day.getFullYear() + "-";
    str += num2str(day.getMonth() + 1) + "-";
    str += num2str(day.getDate()) + " ";
    str += num2str(day.getHours()) + ":";
    str += num2str(day.getMinutes()) + ":";
    str += num2str(day.getSeconds());
    return str;
   }
 
   private function num2str(val:Number):String {
    var str:String = "00" + val;
    return str.substr(str.length - 2, 2);  
   }
 
   private function debug(message:String):void {
    _state_txt.text = message;
   }
 
}