ios原生二维码扫描

实现AVCaptureMetadataOutputObjectsDelegate协议方法

#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];
  //判断回传的数据类型
  if ([[metadataObj type] isEqualToString:AVMetadataObjectTypeQRCode]) {
   [_lblStatus performSelectorOnMainThread:@selector(setText:) withObject:[metadataObj stringValue] waitUntilDone:NO];
   [self performSelectorOnMainThread:@selector(stopReading) withObject:nil waitUntilDone:NO];
   _isReading = NO;
  }
 }
}

- (void)moveScanLayer:(NSTimer *)timer
{
 CGRect frame = _scanLayer.frame;
 if (_boxView.frame.size.height < _scanLayer.frame.origin.y) {
  frame.origin.y = 0;
  _scanLayer.frame = frame;
 }else{
  frame.origin.y += 5;
  [UIView animateWithDuration:0.1 animations:^{
   _scanLayer.frame = frame;
  }];
 }
}

- (IBAction)startStopReading:(id)sender {
  if (!_isReading) {
   if ([self startReading]) {
    [_startBtn setTitle:@"Stop" forState:UIControlStateNormal];
    [_lblStatus setText:@"Scanning for QR Code"];
   }
  }
  else{
   [self stopReading];
   [_startBtn setTitle:@"Start!" forState:UIControlStateNormal];
  }
  _isReading = !_isReading;
}
-(void)stopReading{
 [_captureSession stopRunning];
 _captureSession = nil;
 [_scanLayer removeFromSuperlayer];
 [_videoPreviewLayer removeFromSuperlayer];
}