iOS原生的AVFoundation扫描二维码/条形码

#import <AVFoundation/AVFoundation.h>

@interface ViewController ()<AVCaptureMetadataOutputObjectsDelegate>

//扫描条形码
@property (strong, nonatomic) UIView *boxView;
@property (strong, nonatomic) UILabel *lblStatus;
@property (strong, nonatomic) CALayer *scanLayer;

//捕捉会话
@property (nonatomic, strong) AVCaptureSession *captureSession;
//展示layer
@property (nonatomic, strong) AVCaptureVideoPreviewLayer *videoPreviewLayer;

//扫描二维码
- (void)clickSaoMiaoBtn
{
    [self startReading];
}
- (BOOL)startReading {
    NSError *error;
    //1.初始化捕捉设备（AVCaptureDevice），类型为AVMediaTypeVideo
    AVCaptureDevice *captureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
    //2.用captureDevice创建输入流
    AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:captureDevice error:&error];
    if (!input) {
        NSLog(@"%@", [error localizedDescription]);
        return NO;
    }    
    //3.创建媒体数据输出流
    AVCaptureMetadataOutput *captureMetadataOutput = [[AVCaptureMetadataOutput alloc] init];
    //4.实例化捕捉会话
    _captureSession = [[AVCaptureSession alloc] init];
    //4.1.将输入流添加到会话
    [_captureSession addInput:input];
    //4.2.将媒体输出流添加到会话中
    [_captureSession addOutput:captureMetadataOutput];
    //5.创建串行队列，并加媒体输出流添加到队列当中
    dispatch_queue_t dispatchQueue;
    dispatchQueue = dispatch_queue_create("myQueue", NULL);
    //5.1.设置代理
    [captureMetadataOutput setMetadataObjectsDelegate:self queue:dispatchQueue];
    //5.2.设置输出媒体数据类型为QRCode
    [captureMetadataOutput setMetadataObjectTypes:[NSArray arrayWithObjects:AVMetadataObjectTypeEAN13Code, AVMetadataObjectTypeEAN8Code, AVMetadataObjectTypeCode128Code,nil]];
    //6.实例化预览图层
    _videoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:_captureSession];
    //7.设置预览图层填充方式
    [_videoPreviewLayer setVideoGravity:AVLayerVideoGravityResizeAspectFill];
    //8.设置图层的frame
    [_videoPreviewLayer setFrame:self.view.layer.bounds];
    //9.将图层添加到预览view的图层上
    [self.view.layer addSublayer:_videoPreviewLayer];
    //10.设置扫描范围
    captureMetadataOutput.rectOfInterest = CGRectMake(0.2f, 0.2f, 0.6f, 0.6f);
    //10.1.扫描框
    _boxView = [[UIView alloc] initWithFrame:CGRectMake(WIDTH * 0.2f, HEIGHT * 0.2f, WIDTH - WIDTH * 0.4f, HEIGHT - HEIGHT * 0.4f)];
    _boxView.layer.borderColor = [UIColor orangeColor].CGColor;
    _boxView.layer.borderWidth = 2.0f;
    [self.view addSubview:_boxView];
    //10.2.扫描线
    _scanLayer = [[CALayer alloc] init];
    _scanLayer.frame = CGRectMake(0, 0, _boxView.bounds.size.width, 1);
    _scanLayer.backgroundColor = [UIColor redColor].CGColor;
    [_boxView.layer addSublayer:_scanLayer];
    NSTimer *timer = [NSTimer scheduledTimerWithTimeInterval:0.1f target:self selector:@selector(moveScanLayer:) userInfo:nil repeats:YES];
    [timer fire];
    //10.开始扫描
    [_captureSession startRunning];
    return YES;
}

#pragma mark - AVCaptureMetadataOutputObjectsDelegate
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection
{
    //判断是否有数据
    if (metadataObjects != nil && [metadataObjects count] > 0) {
        AVMetadataMachineReadableCodeObject *metadataObj = [metadataObjects objectAtIndex:0];
        
        dispatch_async(dispatch_get_main_queue(), ^{
            
            self.searchTF.text = [metadataObj stringValue];
            [self stopReading];
        });
        
    }
}

- (void)moveScanLayer:(NSTimer *)timer
{
    CGRect frame = _scanLayer.frame;
    if (_boxView.frame.size.height < _scanLayer.frame.origin.y +50*hl) {
        _scanLayer.frame = CGRectMake(0, 0, _boxView.bounds.size.width, 1);
    }else{
        frame.origin.y += 20*hl;
        [UIView animateWithDuration:0.01f animations:^{
            _scanLayer.frame = frame;
        }];
    }
}

-(void)stopReading{
    [_captureSession stopRunning];
    _captureSession = nil;
    [_scanLayer removeFromSuperlayer];
    [_videoPreviewLayer removeFromSuperlayer];
    [_boxView removeFromSuperview];
}