使用AVCaptureMetadataOutput和AVFoundation扫描条形码 [英] Scanning barcode with AVCaptureMetadataOutput and AVFoundation
本文介绍了使用AVCaptureMetadataOutput和AVFoundation扫描条形码的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我正在使用AVFoundation和AVCaptureMetadataOutput来扫描iOS7中的QR条形码,我提供了一个允许用户扫描条形码的视图控制器。它工作正常,即。正在扫描条形码,我可以将条形码字符串输出到控制台。
I am using AVFoundation and AVCaptureMetadataOutput to scan a QR barcode in iOS7, I present a view controller which allows the user to scan a barcode. It is working fine, ie. a barcode is being scanned and I can output the barcode string to console.
但是它会一遍又一遍地扫描,看屏幕截图。我想要它做的是扫描条形码只是一次然后dismissViewController。
But it keeps scanning over and over again, see screen shot. What I want it to do is scan the barcode just the once and then dismissViewController.
这是我的代理方法的代码:
Here is my code for the delegate method:
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection
{
CGRect highlightViewRect = CGRectZero;
AVMetadataMachineReadableCodeObject *barCodeObject;
NSString *detectionString = nil;
NSArray *barCodeTypes = @[AVMetadataObjectTypeUPCECode, AVMetadataObjectTypeCode39Code, AVMetadataObjectTypeCode39Mod43Code,
AVMetadataObjectTypeEAN13Code, AVMetadataObjectTypeEAN8Code, AVMetadataObjectTypeCode93Code, AVMetadataObjectTypeCode128Code,
AVMetadataObjectTypePDF417Code, AVMetadataObjectTypeQRCode, AVMetadataObjectTypeAztecCode];
for (AVMetadataObject *metadata in metadataObjects) {
for (NSString *type in barCodeTypes) {
if ([metadata.type isEqualToString:type])
{
barCodeObject = (AVMetadataMachineReadableCodeObject *)[self.preview transformedMetadataObjectForMetadataObject:(AVMetadataMachineReadableCodeObject *)metadata];
highlightViewRect = barCodeObject.bounds;
detectionString = [(AVMetadataMachineReadableCodeObject *)metadata stringValue];
break;
}
}
if (detectionString != nil)
{
NSLog(@"Barcode: %@", detectionString);
break;
}
else
NSLog(@"None");
}
self.highlightView.frame = highlightViewRect;
}
推荐答案
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection
{
....
self.highlightView.frame = highlightViewRect;
[_session stopRunning]; //<---I add this and it worked for me.
}
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