WPF中的Bitmap与byte

 public MainWindow()
        {
            InitializeComponent();
            byte[] b = GetPictureData(@"F:\WPF\TestSolution\TestReatByteFromDB\Images\123.png");
            BitmapImage myimg = ByteArrayToBitmapImage(b);
            this.testImg.Source = myimg;
        }

        public byte[] GetPictureData(string imagepath)
        {
            /**/
            ////根据图片文件的路径使用文件流打开，并保存为byte[] 
            FileStream fs = new FileStream(imagepath, FileMode.Open);//可以是其他重载方法 
            byte[] byData = new byte[fs.Length];
            fs.Read(byData, 0, byData.Length);
            fs.Close();
            return byData;
        }

        public BitmapImage ByteArrayToBitmapImage(byte[] byteArray)
        {
            BitmapImage bmp = null;

            try
            {
                bmp = new BitmapImage();
                bmp.BeginInit();
                bmp.StreamSource = new MemoryStream(byteArray);
                bmp.EndInit();
            }
            catch
            {
                bmp = null;
            }

            return bmp;
        }

        public byte[] BitmapImageToByteArray(BitmapImage bmp)
        {
            byte[] byteArray = null;

            try
            {
                Stream sMarket = bmp.StreamSource;

                if (sMarket != null && sMarket.Length > 0)
                {
                    //很重要，因为Position经常位于Stream的末尾，导致下面读取到的长度为0。 
                    sMarket.Position = 0;

                    using (BinaryReader br = new BinaryReader(sMarket))
                    {
                        byteArray = br.ReadBytes((int)sMarket.Length);
                    }
                }
            }
            catch
            {
                //other exception handling 
            }

            return byteArray;
        }