base64编码在silverlight中的使用

< UserControl  x:Class ="SLBase64.MainPage"
    xmlns ="http://schemas.microsoft.com/winfx/2006/xaml/presentation"  
    xmlns:x ="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d ="http://schemas.microsoft.com/expression/blend/2008"  xmlns:mc ="http://schemas.openxmlformats.org/markup-compatibility/2006"  
    mc:Ignorable ="d"  d:DesignWidth ="640"  d:DesignHeight ="480" >
   < StackPanel  x:Name ="LayoutRoot" >
         < Image   x:Name ="img"  Height ="100"  Stretch ="Uniform"  Source ="img/self.png" ></ Image >
         < Button  x:Name ="btnToBase64"  Content ="转为base64字符串"  Width ="200"  Margin ="0,3,0,0"   Click ="btnToBase64_Click" ></ Button >
         < TextBox  Text =""  x:Name ="txtBase64"  TextWrapping ="Wrap"  Height ="150"  Margin ="0,3"  VerticalScrollBarVisibility ="Auto" ></ TextBox >
         < Button  x:Name ="btnToImg"  Content ="将上述base64字符串还原为图片"  Width ="200"  Margin ="0,0,0,3"  Click ="btnToImg_Click" ></ Button >
         < Image   x:Name ="img2"  Height ="100"  Stretch ="Uniform" ></ Image >
     </ StackPanel >
</ UserControl >

using  System;
using  System.IO;
using  System.Windows;
using  System.Windows.Controls;
using  System.Windows.Media.Imaging;
using  FluxJpeg.Core;
using  FluxJpeg.Core.Encoder;

namespace  SLBase64
{
     public   partial   class  MainPage : UserControl
    {
         public  MainPage()
        {
            InitializeComponent();
        }

         ///   <summary>
         ///  老外写的方法：将WriteableBitmap转化为base64位字符串
         ///   </summary>
         ///   <param name="bitmap"></param>
         ///   <returns></returns>
         private   string  GetBase64Image(WriteableBitmap bitmap)
        {
             int  width  =  bitmap.PixelWidth;
             int  height  =  bitmap.PixelHeight;
             int  bands  =   3 ;
             byte [][,] raster  =   new   byte [bands][,];

             for  ( int  i  =   0 ; i  <  bands; i ++ )
            {
                raster[i]  =   new   byte [width, height];
            }

             for  ( int  row  =   0 ; row  <  height; row ++ )
            {
                 for  ( int  column  =   0 ; column  <  width; column ++ )
                {
                     int  pixel  =  bitmap.Pixels[width  *  row  +  column];
                    raster[ 0 ][column, row]  =  ( byte )(pixel  >>   16 );
                    raster[ 1 ][column, row]  =  ( byte )(pixel  >>   8 );
                    raster[ 2 ][column, row]  =  ( byte )pixel;
                }
            }

            ColorModel model  =   new  ColorModel { colorspace  =  ColorSpace.RGB };
            FluxJpeg.Core.Image img  =   new  FluxJpeg.Core.Image(model, raster);
            MemoryStream stream  =   new  MemoryStream();
            JpegEncoder encoder  =   new  JpegEncoder(img,  100 , stream);
            encoder.Encode();

            stream.Seek( 0 , SeekOrigin.Begin);
             byte [] binaryData  =   new  Byte[stream.Length];
             long  bytesRead  =  stream.Read(binaryData,  0 , ( int )stream.Length);

             string  base64String  =
                    System.Convert.ToBase64String(binaryData,
                                                   0 ,
                                                  binaryData.Length);

             return  base64String;

        }

         private   void  btnToBase64_Click( object  sender, RoutedEventArgs e)
        {
            WriteableBitmap wb  =   new  WriteableBitmap(img,  null );
            txtBase64.Text  =   "" ;
            txtBase64.Text  =  GetBase64Image(wb);
        }

         private   void  btnToImg_Click( object  sender, RoutedEventArgs e)
        {
             if  (txtBase64.Text  ==   "" ) {  return ; }
             try
            {
                img2.Source  =   null ;

                 byte [] b  =  Convert.FromBase64String(txtBase64.Text);
                MemoryStream ms  =   new  MemoryStream(b);
                BitmapImage bitImage  =   new  BitmapImage();
                bitImage.SetSource(ms);

                img2.Source  =  bitImage;
            }
             catch  (Exception ex) { MessageBox.Show(ex.Message.ToString()); }
        }
    }
}