as3 屏幕截图教程(附源码及代码说明)

////////////////////////////////// as源码
//////////////////////////////////

import JPGEncoder;

//设置要截屏的范围

var jpg:BitmapData=new
BitmapData(stage.stageWidth,stage.stageHeight);//图片大小

jpg.draw(root);//截取整个舞台var jpgCode:JPGEncoder=new
JPGEncoder(85);//设置编码器(图片品质)

var
jpgStream:ByteArray=jpgCode.encode(jpg);//对截取的图片进行编码//和PHP交互

var url:URLRequestHeader=new URLRequestHeader("Content-type",
"application/octet-stream");

var request:URLRequest = new
URLRequest("download.php?name=jpg.jpg");

request.requestHeaders.push(url);

request.method = URLRequestMethod.POST;

request.data = jpgStream;

navigateToURL(request, "_blank");////////////////////////////////// PHP源码
//////////////////////////////////

<?phpif (isset($GLOBALS["HTTP_RAW_POST_DATA"]))

{

// get bytearray

$jpg = $GLOBALS["HTTP_RAW_POST_DATA"];


// add headers for download dialog-box

header("=Content-Type: image/jpeg");

header("Content-Disposition: attachment;
filename=".$_GET["name"]);

echo $jpg;

}?>
//////////////////////////////////
JPGEncoder源码 //////////////////////////////////

package {

import flash.geom.*;

import flash.display.*;

import flash.utils.*;


  

public class JPGEncoder

{   // Static
table initialization


   private var ZigZag:Array =
[

    0, 1, 5,
6,14,15,27,28,

    2, 4,
7,13,16,26,29,42,

    3,
8,12,17,25,30,41,43,

   
9,11,18,24,31,40,44,53,

   
10,19,23,32,39,45,52,54,

   
20,22,33,38,46,51,55,60,

   
21,34,37,47,50,56,59,61,

   
35,36,48,49,57,58,62,63

   ];


   private var YTable:Array = new
Array(64);

   private var UVTable:Array =
new Array(64);

   private var fdtbl_Y:Array =
new Array(64);

   private var fdtbl_UV:Array =
new Array(64);


   private function
initQuantTables(sf:int):void

   {

    var
i:int;

    var
t:Number;

    var
YQT:Array = [

    
16, 11, 10, 16, 24, 40, 51, 61,

    
12, 12, 14, 19, 26, 58, 60, 55,

    
14, 13, 16, 24, 40, 57, 69, 56,

    
14, 17, 22, 29, 51, 87, 80, 62,

    
18, 22, 37, 56, 68,109,103, 77,

    
24, 35, 55, 64, 81,104,113, 92,

    
49, 64, 78, 87,103,121,120,101,

    
72, 92, 95, 98,112,100,103, 99

    ];

    for (i = 0;
i < 64; i++) {

    
t = Math.floor((YQT[i]*sf+50)/100);

    
if (t < 1) {

     
t = 1;

    
} else if (t > 255) {

     
t = 255;

    
}

    
YTable[ZigZag[i]] = t;

    }

    var
UVQT:Array = [

    
17, 18, 24, 47, 99, 99, 99, 99,

    
18, 21, 26, 66, 99, 99, 99, 99,

    
24, 26, 56, 99, 99, 99, 99, 99,

    
47, 66, 99, 99, 99, 99, 99, 99,

    
99, 99, 99, 99, 99, 99, 99, 99,

    
99, 99, 99, 99, 99, 99, 99, 99,

    
99, 99, 99, 99, 99, 99, 99, 99,

    
99, 99, 99, 99, 99, 99, 99, 99

    ];

    for (i = 0;
i < 64; i++) {

    
t = Math.floor((UVQT[i]*sf+50)/100);

    
if (t < 1) {

     
t = 1;

    
} else if (t > 255) {

     
t = 255;

    
}

    
UVTable[ZigZag[i]] = t;

    }

    var
aasf:Array = [

    
1.0, 1.387039845, 1.306562965, 1.175875602,

    
1.0, 0.785694958, 0.541196100, 0.275899379

    ];

    i = 0;

    for (var
row:int = 0; row < 8; row++)

    {

    
for (var col:int = 0; col < 8; col++)

    
{

     
fdtbl_Y[i] = (1.0 / (YTable [ZigZag[i]] * aasf[row] * aasf[col] *
8.0));

     
fdtbl_UV[i] = (1.0 / (UVTable[ZigZag[i]] * aasf[row] * aasf[col] *
8.0));

     
i++;