WindowsPhone8.1 开发-- 二维码扫描

<Grid x:Name="LayoutRoot" Background="Black">
<Grid Background="Black">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="50"/>
<ColumnDefinition Width="300"/>
<ColumnDefinition Width="50"/>
</Grid.ColumnDefinitions>
<Grid Grid.Column="0" Height="366" Margin="0,0,0,0"> </Grid>
<!--取景器区域-->
<Grid Grid.Column="1" x:Name="ScanViewGrid" Margin="0,0,0,0">
<Grid.Resources>
<Storyboard x:Name="myStoryboard">
<DoubleAnimation
Storyboard.TargetName="imgScan"
Storyboard.TargetProperty="(Canvas.Top)"
Duration="0:0:2.5"
From="0"
To="300"
RepeatBehavior="Forever"/>
</Storyboard>
</Grid.Resources>
<!--扫描线--> <Canvas Width="300" Canvas.Top="170" Height="300">
<CaptureElement Stretch="UniformToFill" x:Name="VideoCapture" Width="300" Height="300" > </CaptureElement>
<Image x:Name="imgScan" Source="/Assets/img/light.png" Width="300" Height="40" Stretch="Fill"/> <Image x:Name="CaptureImage" Width="300" Height="300" Visibility="Collapsed" />
</Canvas> </Grid>
<Grid Grid.Column="2" Margin="0,0,0,0"/>
</Grid> <TextBlock x:Name="Error" VerticalAlignment="Bottom" FontSize="32" Width="400" TextAlignment="Center" />
<TextBlock x:Name="ScanResult" Text="hhh" FontSize="25" Foreground="White" VerticalAlignment="Bottom" TextAlignment="Center" Width="400"/>
</Grid>

public sealed partial class QCodeView : Page
{
private readonly MediaCapture _mediaCapture = new MediaCapture();
private Result _result;
private NavigationHelper navigationHelper;
private ObservableDictionary defaultViewModel = new ObservableDictionary();
private DispatcherTimer _timer; public QCodeView()
{
this.InitializeComponent();
//设备屏幕方向
DisplayInformation.AutoRotationPreferences = DisplayOrientations.Portrait;
///隐藏StatusBar
var statusBar = StatusBar.GetForCurrentView();
statusBar.HideAsync();
this.navigationHelper = new NavigationHelper(this);
this.navigationHelper.LoadState += this.NavigationHelper_LoadState;
this.navigationHelper.SaveState += this.NavigationHelper_SaveState;
} /// <summary>
/// 获取与此 <see cref="Page"/> 关联的 <see cref="NavigationHelper"/>。
/// </summary>
public NavigationHelper NavigationHelper
{
get { return this.navigationHelper; }
} /// <summary>
/// 获取此 <see cref="Page"/> 的视图模型。
/// 可将其更改为强类型视图模型。
/// </summary>
public ObservableDictionary DefaultViewModel
{
get { return this.defaultViewModel; }
} /// <summary>
/// 使用在导航过程中传递的内容填充页。 在从以前的会话
/// 重新创建页时，也会提供任何已保存状态。
/// </summary>
/// <param name="sender">
/// 事件的来源; 通常为 <see cref="NavigationHelper"/>
/// </param>
/// <param name="e">事件数据，其中既提供在最初请求此页时传递给
/// <see cref="Frame.Navigate(Type, Object)"/> 的导航参数，又提供
/// 此页在以前会话期间保留的状态的
/// 字典。 首次访问页面时，该状态将为 null。</param>
private void NavigationHelper_LoadState(object sender, LoadStateEventArgs e)
{
} /// <summary>
/// 保留与此页关联的状态，以防挂起应用程序或
/// 从导航缓存中放弃此页。值必须符合
/// <see cref="SuspensionManager.SessionState"/> 的序列化要求。
/// </summary>
/// <param name="sender">事件的来源；通常为 <see cref="NavigationHelper"/></param>
///<param name="e">提供要使用可序列化状态填充的空字典
///的事件数据。</param>
private void NavigationHelper_SaveState(object sender, SaveStateEventArgs e)
{ } #region NavigationHelper 注册 /// <summary>
/// 此部分中提供的方法只是用于使
/// NavigationHelper 可响应页面的导航方法。
/// <para>
/// 应将页面特有的逻辑放入用于
/// <see cref="NavigationHelper.LoadState"/>
/// 和 <see cref="NavigationHelper.SaveState"/> 的事件处理程序中。
/// 除了在会话期间保留的页面状态之外
/// LoadState 方法中还提供导航参数。
/// </para>
/// </summary>
/// <param name="e">提供导航方法数据和
/// 无法取消导航请求的事件处理程序。</param>
protected override void OnNavigatedTo(NavigationEventArgs e)
{ myStoryboard.Begin();
InitVideoCapture();
InitVideoTimer(); this.navigationHelper.OnNavigatedTo(e);
} /// <summary>
/// 初始化摄像
/// </summary>
private async void InitVideoCapture()
{
///摄像头的检测
var cameras = await DeviceInformation.FindAllAsync(DeviceClass.VideoCapture);
if (cameras.Count < 1)
{
Error.Text = "设备没有摄像头,读取本地资源";
await DecodeStaticResource();
return;
} /// 创建 MediaCaptureInitializationSettings 对象的新实例。
var settings = new MediaCaptureInitializationSettings
{
StreamingCaptureMode = StreamingCaptureMode.AudioAndVideo,
MediaCategory = MediaCategory.Other,
AudioProcessing = Windows.Media.AudioProcessing.Default,
VideoDeviceId = cameras[1].Id
};
//if (cameras.Count == 1)
//{
// settings = new MediaCaptureInitializationSettings { VideoDeviceId = cameras[0].Id }; // 0 => front, 1 => back
//}
//else
//{
// settings = new MediaCaptureInitializationSettings { VideoDeviceId = cameras[1].Id }; // 0 => front, 1 => back
//} await _mediaCapture.InitializeAsync(settings);
VideoCapture.Source = _mediaCapture;
await _mediaCapture.StartPreviewAsync();
}
private void InitVideoTimer()
{
_timer = new DispatcherTimer();
_timer.Interval = TimeSpan.FromSeconds(6);
_timer.Tick += _timer_Tick;
_timer.Start(); }
private bool IsBusy = false;
async void _timer_Tick(object sender, object e)
{
try
{
while (_result == null)
{
if (!IsBusy)
{
IsBusy = true;
///获取焦点
//var autoFocusSupported = _mediaCapture.VideoDeviceController.FocusControl.SupportedFocusModes.Contains(FocusMode.Auto);
//if (autoFocusSupported)
//{
// var focusSettings = new FocusSettings
// {
// Mode = FocusMode.Auto,
// AutoFocusRange = AutoFocusRange.Normal
// };
// _mediaCapture.VideoDeviceController.FocusControl.Configure(focusSettings);
// //await _mediaCapture.VideoDeviceController.FocusControl.FocusAsync().AsTask(_cancellationTokenSource.Token);
//} var photoStorageFile = await KnownFolders.PicturesLibrary.CreateFileAsync("qcode.jpg", CreationCollisionOption.ReplaceExisting);
await _mediaCapture.CapturePhotoToStorageFileAsync(ImageEncodingProperties.CreateJpeg(), photoStorageFile); var stream = await photoStorageFile.OpenReadAsync();
// initialize with 1,1 to get the current size of the image
var writeableBmp = new WriteableBitmap(1, 1);
writeableBmp.SetSource(stream);
// and create it again because otherwise the WB isn't fully initialized and decoding
// results in a IndexOutOfRange
writeableBmp = new WriteableBitmap(writeableBmp.PixelWidth, writeableBmp.PixelHeight);
stream.Seek(0);
writeableBmp.SetSource(stream);
_result = ScanBitmap(writeableBmp);
await photoStorageFile.DeleteAsync(StorageDeleteOption.PermanentDelete);
}
if (_result != null)
{
await _mediaCapture.StopPreviewAsync();
VideoCapture.Visibility = Visibility.Collapsed;
CaptureImage.Visibility = Visibility.Visible;
ScanResult.Text = _result.Text;
_timer.Stop();
myStoryboard.Stop();
imgScan.Visibility = Visibility.Collapsed; }
IsBusy = false; }
}
catch (Exception ex)
{ IsBusy = false;
//Error.Text = ex.Message;
}
}
/// <summary>
/// 读取本地资源
/// </summary>
/// <returns></returns>
private async System.Threading.Tasks.Task DecodeStaticResource()
{
var file = await Windows.ApplicationModel.Package.Current.InstalledLocation.GetFileAsync(@"Assets\1.png");
var stream = await file.OpenReadAsync();
// initialize with 1,1 to get the current size of the image
var writeableBmp = new WriteableBitmap(1, 1);
writeableBmp.SetSource(stream);
// and create it again because otherwise the WB isn't fully initialized and decoding
// results in a IndexOutOfRange
writeableBmp = new WriteableBitmap(writeableBmp.PixelWidth, writeableBmp.PixelHeight);
stream.Seek(0);
writeableBmp.SetSource(stream);
CaptureImage.Source = writeableBmp;
VideoCapture.Visibility = Visibility.Collapsed;
CaptureImage.Visibility = Visibility.Visible; _result = ScanBitmap(writeableBmp);
if (_result != null)
{
ScanResult.Text += _result.Text;
}
return;
}
/// <summary>
/// 解析二维码图片
/// </summary>
/// <param name="writeableBmp">拍摄的图片</param>
/// <returns></returns>
private Result ScanBitmap(WriteableBitmap writeableBmp)
{
var barcodeReader = new BarcodeReader
{
TryHarder = true,
AutoRotate = true
};
var result = barcodeReader.Decode(writeableBmp); if (result != null)
{
CaptureImage.Source = writeableBmp;
} return result;
}
/// <summary>
/// 页面离开时对_mediaCapture对象进行释放
/// 防止内存溢出及资源占用
/// </summary>
/// <param name="e"></param>
protected override async void OnNavigatedFrom(NavigationEventArgs e)
{
try
{
await _mediaCapture.StopPreviewAsync();
await _mediaCapture.StopRecordAsync();
_mediaCapture.Dispose();
}
catch (Exception)
{ }
this.navigationHelper.OnNavigatedFrom(e);
}
#endregion
}