public Task <MobileResult> Scan(Context context, MobileBarcodeScanningOptions options)
{
var ctx = GetContext(context);
var task = Task.Factory.StartNew(() => {
var waitScanResetEvent = new System.Threading.ManualResetEvent(false);
var scanIntent = new Intent(ctx, typeof(ZxingActivity));
scanIntent.AddFlags(ActivityFlags.NewTask);
ZxingActivity.UseCustomOverlayView = this.UseCustomOverlay;
ZxingActivity.CustomOverlayView = this.CustomOverlay;
ZxingActivity.ScanningOptions = options;
ZxingActivity.ScanContinuously = false;
ZxingActivity.TopText = TopText;
ZxingActivity.BottomText = BottomText;
MobileResult scanResult = null;
ZxingActivity.CanceledHandler = () =>
{
waitScanResetEvent.Set();
};
ZxingActivity.ScanCompletedHandler = (MobileResult result) =>
{
scanResult = result;
waitScanResetEvent.Set();
};
ctx.StartActivity(scanIntent);
waitScanResetEvent.WaitOne();
return(scanResult);
});
return(task);
}
bool SetupCaptureSession()
{
var availableResolutions = new List <CameraResolution> ();
var consideredResolutions = new Dictionary <NSString, CameraResolution> {
{ AVCaptureSession.Preset352x288, new CameraResolution {
Width = 352, Height = 288
} },
{ AVCaptureSession.PresetMedium, new CameraResolution {
Width = 480, Height = 360
} }, //480x360
{ AVCaptureSession.Preset640x480, new CameraResolution {
Width = 640, Height = 480
} },
{ AVCaptureSession.Preset1280x720, new CameraResolution {
Width = 1280, Height = 720
} },
{ AVCaptureSession.Preset1920x1080, new CameraResolution {
Width = 1920, Height = 1080
} }
};
// configure the capture session for low resolution, change this if your code
// can cope with more data or volume
session = new AVCaptureSession()
{
SessionPreset = AVCaptureSession.Preset640x480
};
// create a device input and attach it to the session
// var captureDevice = AVCaptureDevice.DefaultDeviceWithMediaType (AVMediaType.Video);
AVCaptureDevice captureDevice = null;
var devices = AVCaptureDevice.DevicesWithMediaType(AVMediaType.Video);
foreach (var device in devices)
{
captureDevice = device;
if (ScanningOptions.UseFrontCameraIfAvailable.HasValue &&
ScanningOptions.UseFrontCameraIfAvailable.Value &&
device.Position == AVCaptureDevicePosition.Front)
{
break; //Front camera successfully set
}
else if (device.Position == AVCaptureDevicePosition.Back && (!ScanningOptions.UseFrontCameraIfAvailable.HasValue || !ScanningOptions.UseFrontCameraIfAvailable.Value))
{
break; //Back camera succesfully set
}
}
if (captureDevice == null)
{
Console.WriteLine("No captureDevice - this won't work on the simulator, try a physical device");
if (overlayView != null)
{
this.AddSubview(overlayView);
this.BringSubviewToFront(overlayView);
}
return(false);
}
CameraResolution resolution = null;
// Find resolution
// Go through the resolutions we can even consider
foreach (var cr in consideredResolutions)
{
// Now check to make sure our selected device supports the resolution
// so we can add it to the list to pick from
if (captureDevice.SupportsAVCaptureSessionPreset(cr.Key))
{
availableResolutions.Add(cr.Value);
}
}
resolution = ScanningOptions.GetResolution(availableResolutions);
// See if the user selected a resolution
if (resolution != null)
{
// Now get the preset string from the resolution chosen
var preset = (from c in consideredResolutions
where c.Value.Width == resolution.Width &&
c.Value.Height == resolution.Height
select c.Key).FirstOrDefault();
// If we found a matching preset, let's set it on the session
if (!string.IsNullOrEmpty(preset))
{
session.SessionPreset = preset;
}
}
var input = AVCaptureDeviceInput.FromDevice(captureDevice);
if (input == null)
{
Console.WriteLine("No input - this won't work on the simulator, try a physical device");
if (overlayView != null)
{
this.AddSubview(overlayView);
this.BringSubviewToFront(overlayView);
}
return(false);
}
else
{
session.AddInput(input);
}
foundResult = false;
//Detect barcodes with built in avcapture stuff
AVCaptureMetadataOutput metadataOutput = new AVCaptureMetadataOutput();
captureDelegate = new CaptureDelegate(metaDataObjects =>
{
if (!analyzing)
{
return;
}
//Console.WriteLine("Found MetaData Objects");
var msSinceLastPreview = (DateTime.UtcNow - lastAnalysis).TotalMilliseconds;
if (msSinceLastPreview < ScanningOptions.DelayBetweenAnalyzingFrames ||
(wasScanned && msSinceLastPreview < ScanningOptions.DelayBetweenContinuousScans) ||
working)
//|| CancelTokenSource.IsCancellationRequested)
{
return;
}
try {
working = true;
wasScanned = false;
lastAnalysis = DateTime.UtcNow;
var mdo = metaDataObjects.FirstOrDefault();
var readableObj = mdo as AVMetadataMachineReadableCodeObject;
if (readableObj == null)
{
return;
}
wasScanned = true;
var zxingFormat = ZXingBarcodeFormatFromAVCaptureBarcodeFormat(readableObj.Type.ToString());
var rs = new ZXing.Result(readableObj.StringValue, null, null, zxingFormat);
var resultWithSource = new MobileResult(rs, null);
resultCallback(resultWithSource);
} finally {
working = false;
}
});
metadataOutput.SetDelegate(captureDelegate, DispatchQueue.MainQueue);
session.AddOutput(metadataOutput);
//Setup barcode formats
if (ScanningOptions.PossibleFormats != null && ScanningOptions.PossibleFormats.Count > 0)
{
#if __UNIFIED__
var formats = AVMetadataObjectType.None;
foreach (var f in ScanningOptions.PossibleFormats)
{
formats |= AVCaptureBarcodeFormatFromZXingBarcodeFormat(f);
}
formats &= ~AVMetadataObjectType.None;
metadataOutput.MetadataObjectTypes = formats;
#else
var formats = new List <string> ();
foreach (var f in ScanningOptions.PossibleFormats)
{
formats.AddRange(AVCaptureBarcodeFormatFromZXingBarcodeFormat(f));
}
metadataOutput.MetadataObjectTypes = (from f in formats.Distinct() select new NSString(f)).ToArray();
#endif
}
else
{
metadataOutput.MetadataObjectTypes = metadataOutput.AvailableMetadataObjectTypes;
}
previewLayer = new AVCaptureVideoPreviewLayer(session);
// //Framerate set here (15 fps)
// if (previewLayer.RespondsToSelector(new Selector("connection")))
// {
// if (UIDevice.CurrentDevice.CheckSystemVersion (7, 0))
// {
// var perf1 = PerformanceCounter.Start ();
// NSError lockForConfigErr = null;
// captureDevice.LockForConfiguration (out lockForConfigErr);
// if (lockForConfigErr == null)
// {
// captureDevice.ActiveVideoMinFrameDuration = new CMTime (1, 10);
// captureDevice.UnlockForConfiguration ();
// }
// PerformanceCounter.Stop (perf1, "PERF: ActiveVideoMinFrameDuration Took {0} ms");
// }
// else
// previewLayer.Connection.VideoMinFrameDuration = new CMTime(1, 10);
// }
#if __UNIFIED__
previewLayer.VideoGravity = AVLayerVideoGravity.ResizeAspectFill;
#else
previewLayer.LayerVideoGravity = AVLayerVideoGravity.ResizeAspectFill;
#endif
previewLayer.Frame = new CGRect(0, 0, this.Frame.Width, this.Frame.Height);
previewLayer.Position = new CGPoint(this.Layer.Bounds.Width / 2, (this.Layer.Bounds.Height / 2));
layerView = new UIView(new CGRect(0, 0, this.Frame.Width, this.Frame.Height));
layerView.AutoresizingMask = UIViewAutoresizing.FlexibleWidth | UIViewAutoresizing.FlexibleHeight;
layerView.Layer.AddSublayer(previewLayer);
this.AddSubview(layerView);
ResizePreview(UIApplication.SharedApplication.StatusBarOrientation);
if (overlayView != null)
{
this.AddSubview(overlayView);
this.BringSubviewToFront(overlayView);
//overlayView.LayoutSubviews ();
}
session.StartRunning();
Console.WriteLine("RUNNING!!!");
//output.AlwaysDiscardsLateVideoFrames = true;
Console.WriteLine("SetupCamera Finished");
//session.AddOutput (output);
//session.StartRunning ();
if (captureDevice.IsFocusModeSupported(AVCaptureFocusMode.ContinuousAutoFocus))
{
NSError err = null;
if (captureDevice.LockForConfiguration(out err))
{
if (captureDevice.IsFocusModeSupported(AVCaptureFocusMode.ContinuousAutoFocus))
{
captureDevice.FocusMode = AVCaptureFocusMode.ContinuousAutoFocus;
}
else if (captureDevice.IsFocusModeSupported(AVCaptureFocusMode.AutoFocus))
{
captureDevice.FocusMode = AVCaptureFocusMode.AutoFocus;
}
if (captureDevice.IsExposureModeSupported(AVCaptureExposureMode.ContinuousAutoExposure))
{
captureDevice.ExposureMode = AVCaptureExposureMode.ContinuousAutoExposure;
}
else if (captureDevice.IsExposureModeSupported(AVCaptureExposureMode.AutoExpose))
{
captureDevice.ExposureMode = AVCaptureExposureMode.AutoExpose;
}
if (captureDevice.IsWhiteBalanceModeSupported(AVCaptureWhiteBalanceMode.ContinuousAutoWhiteBalance))
{
captureDevice.WhiteBalanceMode = AVCaptureWhiteBalanceMode.ContinuousAutoWhiteBalance;
}
else if (captureDevice.IsWhiteBalanceModeSupported(AVCaptureWhiteBalanceMode.AutoWhiteBalance))
{
captureDevice.WhiteBalanceMode = AVCaptureWhiteBalanceMode.AutoWhiteBalance;
}
if (UIDevice.CurrentDevice.CheckSystemVersion(7, 0) && captureDevice.AutoFocusRangeRestrictionSupported)
{
captureDevice.AutoFocusRangeRestriction = AVCaptureAutoFocusRangeRestriction.Near;
}
if (captureDevice.FocusPointOfInterestSupported)
{
captureDevice.FocusPointOfInterest = new CGPoint(0.5f, 0.5f);
}
if (captureDevice.ExposurePointOfInterestSupported)
{
captureDevice.ExposurePointOfInterest = new CGPoint(0.5f, 0.5f);
}
captureDevice.UnlockForConfiguration();
}
else
{
Console.WriteLine("Failed to Lock for Config: " + err.Description);
}
}
return(true);
}
public async Task StartScanningAsync(Action <MobileResult> scanCallback, MobileBarcodeScanningOptions options = null)
{
if (stopping)
{
return;
}
displayRequest.RequestActive();
isAnalyzing = true;
ScanCallback = scanCallback;
ScanningOptions = options ?? MobileBarcodeScanningOptions.Default;
topText.Text = TopText ?? string.Empty;
bottomText.Text = BottomText ?? string.Empty;
if (UseCustomOverlay)
{
gridCustomOverlay.Children.Clear();
if (CustomOverlay != null)
{
gridCustomOverlay.Children.Add(CustomOverlay);
}
gridCustomOverlay.Visibility = Visibility.Visible;
gridDefaultOverlay.Visibility = Visibility.Collapsed;
}
else
{
gridCustomOverlay.Visibility = Visibility.Collapsed;
gridDefaultOverlay.Visibility = Visibility.Visible;
}
// Find which device to use
var preferredCamera = await GetFilteredCameraOrDefaultAsync(ScanningOptions);
if (preferredCamera == null)
{
System.Diagnostics.Debug.WriteLine("No camera available");
isMediaCaptureInitialized = false;
return;
}
if (preferredCamera.EnclosureLocation == null || preferredCamera.EnclosureLocation.Panel == Windows.Devices.Enumeration.Panel.Unknown)
{
// No information on the location of the camera, assume it's an external camera, not integrated on the device.
externalCamera = true;
}
else
{
// Camera is fixed on the device.
externalCamera = false;
// Only mirror the preview if the camera is on the front panel.
mirroringPreview = preferredCamera.EnclosureLocation.Panel == Windows.Devices.Enumeration.Panel.Front;
}
mediaCapture = new MediaCapture();
// Initialize the capture with the settings above
try
{
await mediaCapture.InitializeAsync(new MediaCaptureInitializationSettings
{
StreamingCaptureMode = StreamingCaptureMode.Video,
VideoDeviceId = preferredCamera.Id
});
isMediaCaptureInitialized = true;
}
catch (UnauthorizedAccessException)
{
System.Diagnostics.Debug.WriteLine("Denied access to the camera");
}
catch (Exception ex)
{
System.Diagnostics.Debug.WriteLine("Exception when init MediaCapture: {0}", ex);
}
if (!isMediaCaptureInitialized)
{
return;
}
// Set the capture element's source to show it in the UI
captureElement.Source = mediaCapture;
captureElement.FlowDirection = mirroringPreview ? FlowDirection.RightToLeft : FlowDirection.LeftToRight;
// Start the preview
await mediaCapture.StartPreviewAsync();
// Get all the available resolutions for preview
var availableProperties = mediaCapture.VideoDeviceController.GetAvailableMediaStreamProperties(MediaStreamType.VideoPreview);
var availableResolutions = new List <CameraResolution>();
foreach (var ap in availableProperties)
{
var vp = (VideoEncodingProperties)ap;
System.Diagnostics.Debug.WriteLine("Camera Preview Resolution: {0}x{1}", vp.Width, vp.Height);
availableResolutions.Add(new CameraResolution {
Width = (int)vp.Width, Height = (int)vp.Height
});
}
CameraResolution previewResolution = null;
if (ScanningOptions.CameraResolutionSelector != null)
{
previewResolution = ScanningOptions.CameraResolutionSelector(availableResolutions);
}
// If the user did not specify a resolution, let's try and find a suitable one
if (previewResolution == null)
{
// Loop through all supported sizes
foreach (var sps in availableResolutions)
{
// Find one that's >= 640x360 but <= 1000x1000
// This will likely pick the *smallest* size in that range, which should be fine
if (sps.Width >= 640 && sps.Width <= 1000 && sps.Height >= 360 && sps.Height <= 1000)
{
previewResolution = new CameraResolution
{
Width = sps.Width,
Height = sps.Height
};
break;
}
}
}
if (previewResolution == null)
{
previewResolution = availableResolutions.LastOrDefault();
}
if (previewResolution == null)
{
System.Diagnostics.Debug.WriteLine("No preview resolution available. Camera may be in use by another application.");
return;
}
MobileBarcodeScanner.Log("Using Preview Resolution: {0}x{1}", previewResolution.Width, previewResolution.Height);
// Find the matching property based on the selection, again
var chosenProp = availableProperties.FirstOrDefault(ap => ((VideoEncodingProperties)ap).Width == previewResolution.Width && ((VideoEncodingProperties)ap).Height == previewResolution.Height);
// Pass in the requested preview size properties
// so we can set them at the same time as the preview rotation
// to save an additional set property call
await SetPreviewRotationAsync(chosenProp);
// *after* the preview is setup, set this so that the UI layout happens
// otherwise the preview gets stuck in a funny place on screen
captureElement.Stretch = Stretch.UniformToFill;
await SetupAutoFocus();
var zxing = ScanningOptions.BuildBarcodeReader();
timerPreview = new Timer(async(state) => {
var delay = ScanningOptions.DelayBetweenAnalyzingFrames;
if (stopping || processing || !isAnalyzing ||
(mediaCapture == null || mediaCapture.CameraStreamState != Windows.Media.Devices.CameraStreamState.Streaming))
{
timerPreview.Change(delay, Timeout.Infinite);
return;
}
processing = true;
SoftwareBitmapLuminanceSource luminanceSource = null;
try
{
// Get preview
var frame = await mediaCapture.GetPreviewFrameAsync(videoFrame);
// Create our luminance source
luminanceSource = new SoftwareBitmapLuminanceSource(frame.SoftwareBitmap);
} catch (Exception ex)
{
MobileBarcodeScanner.Log("GetPreviewFrame Failed: {0}", ex);
}
ZXing.Result result = null;
try
{
// Try decoding the image
if (luminanceSource != null)
{
result = zxing.Decode(luminanceSource);
}
}
catch (Exception ex)
{
MobileBarcodeScanner.Log("Warning: zxing.Decode Failed: {0}", ex);
}
// Check if a result was found
if (result != null && !string.IsNullOrEmpty(result.Text))
{
if (!ContinuousScanning)
{
delay = Timeout.Infinite;
await Dispatcher.RunAsync(CoreDispatcherPriority.Normal, async() => { await StopScanningAsync(); });
}
else
{
delay = ScanningOptions.DelayBetweenContinuousScans;
}
LastScanResult = new MobileResult(result);
ScanCallback(LastScanResult);
}
processing = false;
timerPreview.Change(delay, Timeout.Infinite);
}, null, ScanningOptions.InitialDelayBeforeAnalyzingFrames, Timeout.Infinite);
}
public Task <MobileResult> Scan(MobileBarcodeScanningOptions options, bool useAVCaptureEngine)
{
return(Task.Factory.StartNew(() => {
try
{
scanResultResetEvent.Reset();
MobileResult result = null;
Version sv = new Version(0, 0, 0);
Version.TryParse(UIDevice.CurrentDevice.SystemVersion, out sv);
var is7orgreater = sv.Major >= 7;
var allRequestedFormatsSupported = true;
if (useAVCaptureEngine)
{
allRequestedFormatsSupported = AVCaptureScannerView.SupportsAllRequestedBarcodeFormats(options.PossibleFormats);
}
this.appController.InvokeOnMainThread(() => {
if (useAVCaptureEngine && is7orgreater && allRequestedFormatsSupported)
{
viewController = new AVCaptureScannerViewController(options, this);
}
else
{
if (useAVCaptureEngine && !is7orgreater)
{
Console.WriteLine("Not iOS 7 or greater, cannot use AVCapture for barcode decoding, using ZXing instead");
}
else if (useAVCaptureEngine && !allRequestedFormatsSupported)
{
Console.WriteLine("Not all requested barcode formats were supported by AVCapture, using ZXing instead");
}
viewController = new ZXing.Mobile.ZXingScannerViewController(options, this);
}
viewController.OnScannedResult += barcodeResult => {
((UIViewController)viewController).InvokeOnMainThread(() => {
viewController.Cancel();
// Handle error situation that occurs when user manually closes scanner in the same moment that a QR code is detected
try {
((UIViewController)viewController).DismissViewController(true, () => {
result = barcodeResult;
scanResultResetEvent.Set();
});
} catch (ObjectDisposedException) {
// In all likelihood, iOS has decided to close the scanner at this point. But just in case it executes the
// post-scan code instead, set the result so we will not get a NullReferenceException.
result = barcodeResult;
scanResultResetEvent.Set();
}
});
};
appController.PresentViewController((UIViewController)viewController, true, null);
});
scanResultResetEvent.WaitOne();
((UIViewController)viewController).Dispose();
return result;
}
catch (Exception ex)
{
Console.WriteLine(ex);
return null;
}
}));
}
