項(xiàng)目地址：https://github.com/tujinqiu/KTQRCode

1、二維碼掃描

- (void)startScan
{
    [self.popView startAnimateScanBar];
    AVCaptureDevice *captureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
    NSError *error = nil;
    AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:captureDevice error:&error];
    NSParameterAssert(input);
    self.captureSession = [[AVCaptureSession alloc] init];
    [self.captureSession addInput:input];
    AVCaptureMetadataOutput *output = [[AVCaptureMetadataOutput alloc] init];
    [self.captureSession addOutput:output];
    dispatch_queue_t queue = dispatch_queue_create("KTScanViewControllerScanQueue", DISPATCH_QUEUE_SERIAL);
    [output setMetadataObjectsDelegate:self queue:queue];
    [output setMetadataObjectTypes:@[AVMetadataObjectTypeQRCode]];
    CGSize size = [UIScreen mainScreen].bounds.size;
    CGRect outputFrame = self.popView.scanFrame;
    [output setRectOfInterest:CGRectMake(outputFrame.origin.y / size.height, outputFrame.origin.x / size.width, outputFrame.size.height / size.height, outputFrame.size.width / size.width)];
    [self.previewLayerView configWithSession:self.captureSession];
    [self.captureSession startRunning];
}

#pragma mark -- AVCaptureMetadataOutputObjectsDelegate --

- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection
{
    if ([metadataObjects count] > 0) {
        AVMetadataMachineReadableCodeObject *obj = [metadataObjects firstObject];
        NSString *result = nil;
        if ([[obj type] isEqualToString:AVMetadataObjectTypeQRCode]) {
            result = obj.stringValue;
        }
        dispatch_sync(dispatch_get_main_queue(), ^{
            [self stopScan];
            KTQRCodeController *controller = (KTQRCodeController *)self.navigationController;
            if (result && [controller.QRCodeDelegate respondsToSelector:@selector(QRCodeController:didScanResult:)]) {
                [controller.QRCodeDelegate QRCodeController:controller didScanResult:result];
            }
        });
    }
}

2悲柱、從相冊識別二維碼

- (void)readQRCodeFromImage:(UIImage *)image result:(void (^)(NSString *resultString))result
{
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        CIImage *ciImage = [CIImage imageWithCGImage:image.CGImage];
        NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:CIDetectorAccuracyHigh, CIDetectorAccuracy, nil];
        CIDetector *detector = [CIDetector detectorOfType:CIDetectorTypeQRCode context:nil options:options];
        NSArray *features = [detector featuresInImage:ciImage];
        NSString *str = nil;
        if (features.count > 0) {
            CIQRCodeFeature *feature = [features firstObject];
            str = feature.messageString;
        }
        if (result) {
            dispatch_async(dispatch_get_main_queue(), ^{
                result(str);
            });
        }
    });
}