iOS 7 AVCaptureMetadataOutput委托(QRCode扫描仪)

Question

我正在尝试使用新的iOS 7功能实现QRCode扫描程序,但我的代码没有调用main AVCaptureMetadataOutputObjectsDelegate方法.

我之前使用过AVFoundation相机并使用我当前的实现我已经预览层运行没有问题.甚至切换回输出以AVCaptureVideoDataOutput验证我的会话设置.

我正在使用这个NSHipster帖子作为指导,这是我的代码到目前为止:

接口:

@import AVFoundation;

@interface QRCodeViewController () <AVCaptureMetadataOutputObjectsDelegate>

@property (strong, nonatomic) AVCaptureDevice* device;
@property (strong, nonatomic) AVCaptureDeviceInput* input;
@property (strong, nonatomic) AVCaptureMetadataOutput* output;
@property (strong, nonatomic) AVCaptureSession* session;
@property (strong, nonatomic) AVCaptureVideoPreviewLayer* preview;

@end

建立:

- (void)setupCamera
{
    // Device
    self.device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];

    // Input
    self.input = [AVCaptureDeviceInput deviceInputWithDevice:self.device error:nil];

    // Output
    self.output = [[AVCaptureMetadataOutput alloc] init];
    [self.output setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];

    // Session
    self.session = [[AVCaptureSession alloc] init];
    [self.session addInput:self.input];
    [self.session addOutput:self.output];

    // Preview
    self.preview = [AVCaptureVideoPreviewLayer layerWithSession:self.session];
    self.preview.videoGravity = AVLayerVideoGravityResizeAspectFill;
    self.preview.frame = CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height);
    [self.view.layer insertSublayer:self.preview atIndex:0];

    // Start
    [self.session startRunning];
}

代表方法:

// DELEGATE METHOD NOT CALLED
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection
{
    NSLog(@"Metadata");
}

任何帮助是极大的赞赏!

Answer 1

我想弄清楚自己.该文件似乎是说,如果你不设置你metadataObjectTypes想要的类型,你不会得到任何电话.但我的iPad Mini的后置摄像头为availableMetadataObjectTypes返回一个空数组.让我们知道你的想法.

编辑:

我只是想通了如果你将AVCaptureMetadataOutput对象添加到会话中,可以填充availableMetadataObjectTypes,你可以添加条形码检测器.然后将调用captureOutput委托,如下所示:

AVCaptureMetadataOutput *output = [[AVCaptureMetadataOutput alloc] init];
[output setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];
[session addOutput:output];
output.metadataObjectTypes = @[AVMetadataObjectTypeQRCode];