windows phone 扫描二维码

在网上找了找扫描二维码的例子，利用ZXing库实现（下载）,提供的Silverlight版本的下载，在网上搜了一下已经有wp的dll可用了，不过网上实现的条码扫描的例子还都是用的Silverlight版本的dll。有个例子感觉写的不错能学到东西，就模仿着写了写。

 public static class BarCodeManager
    {
        internal static Action<string> BarCodeFound;
        internal static Action<Exception> Error;

        static BarCodeManager()
        {

        }

        /// <summary>
        /// 启动条码扫描
        /// </summary>
        /// <param name="barCodeFound">扫描成功执行的操作</param>
        /// <param name="error">扫描失败的操作</param>
        /// <param name="barcodeFormat">编码类型，默认为ean_13条形码</param>
        public static void StartScan(Action<string> barCodeFound, Action<Exception> error, BarcodeFormat barcodeFormat = null)
        {
            var mainFrame = Application.Current.RootVisual as PhoneApplicationFrame;
            if (mainFrame != null)
            {
                if (barcodeFormat == null)
                {
                    barcodeFormat = BarcodeFormat.EAN_13;
                }
                BarCodeFound = barCodeFound;
                Error = error;
                ZXingReader = GetReader(barcodeFormat);

                mainFrame.Navigate(new Uri("/ScanCode.xaml", UriKind.Relative));
            }

        }

        private static Reader zXingReader;

        public static Reader ZXingReader
        {
            get
            {
                if (zXingReader == null)
                {
                    return new EAN13Reader();
                }
                return zXingReader;
            }
            set { BarCodeManager.zXingReader = value; }
        }

        internal static Reader GetReader(BarcodeFormat format)
        {
            Reader r;
            switch (format.Name)
            {
                case "CODE_128":
                    r = new Code128Reader();
                    break;
                case "CODE_39":
                    r = new Code39Reader();
                    break;
                case "EAN_13":
                    r = new EAN13Reader();
                    break;
                case "EAN_8":
                    r = new EAN8Reader();
                    break;
                case "ITF":
                    r = new ITFReader();
                    break;
                case "UPC_A":
                    r = new UPCAReader();
                    break;
                case "UPC_E":
                    r = new UPCEReader();
                    break;
                case "QR_CODE":
                    r = new QRCodeReader();
                    break;
                default:
                    r = null;
                    break;
            }
            return r;
        }
    }

Action<>这个第一次接触到，要扫描条码信息就调用类的StartScan方法，跳转到ScanCode.xaml 启动扫描。通过第一个参数（Action<string> barCodeFound） 返回扫面的结果。

ScanCode.cs代码

public partial class ScanCode : PhoneApplicationPage
    {
        PhotoCamera photocamera;
        VideoBrush videoBrush = new VideoBrush();
        byte[] buffer = null;//存储photocamera 获取的亮度数据
        Result result = null;

        public ScanCode()
        {
            InitializeComponent();
        }

        protected override void OnNavigatedTo(System.Windows.Navigation.NavigationEventArgs e)
        {
            if (photocamera == null)
            {
                photocamera = new PhotoCamera();
                photocamera.Initialized += new EventHandler<CameraOperationCompletedEventArgs>(photocamera_Initialized);
                photocamera.AutoFocusCompleted += new EventHandler<CameraOperationCompletedEventArgs>(photocamera_AutoFocusCompleted);
                video.Fill = videoBrush;
                videoBrush.SetSource(photocamera);
            }

            base.OnNavigatedTo(e);
        }

        protected override void OnNavigatingFrom(System.Windows.Navigation.NavigatingCancelEventArgs e)
        {
            if (photocamera != null)
            {
                //删除事件处理  msdn备注
                photocamera.Initialized -= photocamera_Initialized;
                photocamera.AutoFocusCompleted -= photocamera_AutoFocusCompleted;
                photocamera.CancelFocus();
                photocamera.Dispose();
            }
            base.OnNavigatingFrom(e);
        }
　　　　//对焦操作完成发生
        void photocamera_AutoFocusCompleted(object sender, CameraOperationCompletedEventArgs e)
        {
            result = null;
            try
            {
                while (result == null)
                {
                    var binaryBitmap = GetBitmapFromCamera();
                    if (binaryBitmap != null)
                    {
                        try
                        {
                            result = BarCodeManager.ZXingReader.decode(binaryBitmap);
                        }
                        catch
                        {
                        }
                    }
                }
                if (result != null)
                {
                    BarCodeManager.BarCodeFound(result.Text);
                }
                else
                {
　　　　　　　　　　　　//再次执行相机聚焦操作，也可以用DispatcherTimer周期执行GetBitmapFromCamera获取解码数据
                    photocamera.Focus();
                }
            }
            catch (Exception ex)
            {
                //BarCodeManager.Error(ex);
            }
        }

        void photocamera_Initialized(object sender, CameraOperationCompletedEventArgs e)
        {
            photocamera.FlashMode = FlashMode.Auto;
            photocamera.Focus();
        }
        /// <summary>
        /// 获取摄像头扫描的图像
        /// </summary>
        /// <returns></returns>
        BinaryBitmap GetBitmapFromCamera()
        {

            BinaryBitmap binaeryBitmap = null;
            try
            {
                var pixelWidth = (int)photocamera.PreviewResolution.Width;
                var pixelHeight = (int)photocamera.PreviewResolution.Height;
                if (buffer == null || buffer.Length != (pixelHeight * pixelWidth))
                {
                    buffer = new byte[pixelWidth * pixelHeight];
                }
                //捕捉亮度数据，创建HybridBinarizer和BinaryBitmap类，返回BinaryBitmap给Reade对象解码
                photocamera.GetPreviewBufferY(buffer);
                var luminance = new RGBLuminanceSource(buffer, pixelWidth, pixelHeight, true);
                var binarizer = new HybridBinarizer(luminance);
                binaeryBitmap = new BinaryBitmap(binarizer);
            }
            catch
            {
            }
            return binaeryBitmap;
        }
    }

调用代码，调用StartScan，完成条码扫描，所有的操作完全可以写在一个ScanCode类中，这种设计是可以在封装成一个dll，在外部直接调用

BarCodeManager.StartScan(
                (r) => Dispatcher.BeginInvoke(() =>
                    {
                        tbScanResultBarCode.Text = r;
                        NavigationService.GoBack();
                    }),
                 null
                );

OK！纯属来帖代码来了，，，，，，