如何实现相机视图层的二维码扫描iPhone应用程序？

Question

I am writing iphone application where i want qr code scanning.I have QR code library to scan QR code. And now I want to give QR code scanning interface to my iPhone application.

In Android I could achieve this using SurfaceView that is the view where we can show camera frames. Is there anything available in iPhone equilvalent to surfaceview in Android? If so how to do this. Please give me a tutorial or example links.

Answer 1

- (IBAction)TakePicture:(id)sender {

// Create image picker controller
UIImagePickerController *imagePicker = [[UIImagePickerController alloc] init];

// Set source to the camera
imagePicker.sourceType =  UIImagePickerControllerSourceTypeCamera;

    // Delegate is self
    imagePicker.delegate = self;

    OverlayView *overlay = [[OverlayView alloc] initWithFrame:CGRectMake(0, 0, 320, 480)];     

    // Insert the overlay:
    imagePicker.cameraOverlayView = overlay;

   // Allow editing of image ?
    imagePicker.allowsImageEditing = YES;
    [imagePicker setCameraDevice:
    UIImagePickerControllerCameraDeviceFront];
    [imagePicker setAllowsEditing:YES];
    imagePicker.showsCameraControls=YES;
    imagePicker.navigationBarHidden=YES;
    imagePicker.toolbarHidden=YES;
    imagePicker.wantsFullScreenLayout=YES;

    self.library = [[ALAssetsLibrary alloc] init];

    // Show image picker
    [self presentModalViewController:imagePicker animated:YES];
}

Make a UIView class and add this code

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code


        // Clear the background of the overlay:
        self.opaque = NO;
        self.backgroundColor = [UIColor clearColor];

        // Load the image to show in the overlay:
        UIImage *overlayGraphic = [UIImage imageNamed:@"overlaygraphic.png"];
        UIImageView *overlayGraphicView = [[UIImageView alloc] initWithImage:overlayGraphic];
        overlayGraphicView.frame = CGRectMake(30, 100, 260, 200);
        [self addSubview:overlayGraphicView];

    }
    return self;
}

You can also refer to this link: http://www.musicalgeometry.com/?p=821

Answer 2

QR code detection is readily available in iOS since iOS 7, the trick is to tell a AVCaptureMetadataOutput instance to detect objects with type AVMetadataObjectTypeQRCode .

Live camera preview (with access to pixels if you still want to use that) is in iOS for a long time, easiest with AVCaptureVideoPreviewLayer .

See here for an example http://www.appcoda.com/qr-code-reader-swift/