Flash保存图片到本地

[code]

import flash.events.MouseEvent;
import flash.external.ExternalInterface;
stage.addEventListener(MouseEvent.CLICK, saveImage);

function saveImage(e:MouseEvent):void
{
var saveFile:FileReference = new FileReference();
var pngSource:BitmapData = new BitmapData(stage.stageWidth, stage.stageHeight);
pngSource.draw(stage);
saveFile.save(encode(pngSource), "1.jpg" );
}

function encode(img:BitmapData):ByteArray {
// Create output byte array
var png:ByteArray = new ByteArray();
// Write PNG signature
png.writeUnsignedInt(0x89504e47);
png.writeUnsignedInt(0x0D0A1A0A);
// Build IHDR chunk
var IHDR:ByteArray = new ByteArray();
IHDR.writeInt(img.width);
IHDR.writeInt(img.height);
IHDR.writeUnsignedInt(0x08060000); // 32bit RGBA
IHDR.writeByte(0);
writeChunk(png,0x49484452,IHDR);
// Build IDAT chunk
var IDAT:ByteArray= new ByteArray();
for(var i:int=0;i < img.height;i++) { // no filter IDAT.writeByte(0); var p:uint; var j:int; if ( !img.transparent ) { for(j=0;j < img.width;j++) { p = img.getPixel(j,i); IDAT.writeUnsignedInt( uint(((p&0xFFFFFF) << 8)|0xFF)); } } else { for(j=0;j < img.width;j++) { p = img.getPixel32(j,i); IDAT.writeUnsignedInt( uint(((p&0xFFFFFF) << 8)| (p>>>24)));
}
}
}
IDAT.compress();
writeChunk(png,0x49444154,IDAT);
// Build IEND chunk
writeChunk(png,0x49454E44,null);
// return PNG
return png;
}

var crcTable:Array;
var crcTableComputed:Boolean = false;

function writeChunk(png:ByteArray,
type:uint, data:ByteArray):void {
if (!crcTableComputed) {
crcTableComputed = true;
crcTable = [];
var c:uint;
for (var n:uint = 0; n < 256; n++) { c = n; for (var k:uint = 0; k < 8; k++) { if (c & 1) { c = uint(uint(0xedb88320) ^ uint(c >>> 1));
} else {
c = uint(c >>> 1);
}
}
crcTable[n] = c;
}
}
var len:uint = 0;
if (data != null) {
len = data.length;
}
png.writeUnsignedInt(len);
var p:uint = png.position;
png.writeUnsignedInt(type);
if ( data != null ) {
png.writeBytes(data);
}
var e:uint = png.position;
png.position = p;
c = 0xffffffff;
for (var i:int = 0; i < (e-p); i++) { c = uint(crcTable[ (c ^ png.readUnsignedByte()) & uint(0xff)] ^ uint(c >>> 8));
}
c = uint(c^uint(0xffffffff));
png.position = e;
png.writeUnsignedInt(c);
}

[/code]