iOS 条码及二维码扫描（从相册中读取条形码/二维码）及扫码过程中遇到的坑

<span style="font-size:14px;">//创建输出流 AVCaptureMetadataOutput * output = [[AVCaptureMetadataOutput alloc]init];  //设置识别区域 （这个值是按比例0~1设置，而且X、Y要调换位置，width、height调换位置）   output.rectOfInterest = CGRectMake(Y /ScreenHeight, X /ScreenWidth, height /ScreenHeight, width /ScreenWidth)</span> 

<span style="font-size:14px;">//要实现两个代理方法 <UIImagePickerControllerDelegate,UINavigationControllerDelegate> </span> [objc] view plain copy 在CODE上查看代码片派生到我的代码片<span style="font-size:14px;">-(void)imagePickerController:(UIImagePickerController*)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {   // 创建探测器 CIDetectorTypeQRCode   CIDetector *detector = [CIDetector detectorOfType: CIDetectorTypeText context:nil options:@{CIDetectorAccuracy: CIDetectorAccuracyLow}];     [picker dismissViewControllerAnimated:YES completion:^{     }];   // 取出选中的图片   UIImage *pickImage = info[UIImagePickerControllerOriginalImage];   // 设置数组，放置识别完之后的数据   NSArray *features = [detector featuresInImage:[CIImage imageWithData:UIImagePNGRepresentation(pickImage)]];   // 判断是否有数据（即是否是二维码）   if (features.count >= 1) {     // 取第一个元素就是二维码所存放的文本信息     CIQRCodeFeature *feature = features[0];     NSString *scannedResult = feature.messageString;     // 触发回调     [self getScanDataString:scannedResult];   }else{     [self getScanDataString:@"未识别图片中的二维码"];   } }</span>

#import "ZBarSDK.h"/<span style="font-size:18px;">**  * 获取相册中的二维码图片  */ - (void)getQRcodeImage {   // ZBarsSDK 初始化   ZBarReaderController *imagePicker = [ZBarReaderController new];   imagePicker.showsHelpOnFail = NO; // 禁止显示读取失败页面   imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;   imagePicker.delegate = self;   imagePicker.allowsEditing = YES;   [self presentViewController:imagePicker animated:YES completion:nil]; } /**  * 选中图片的回调  */ -(void)imagePickerController:(UIImagePickerController*)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {   id<NSFastEnumeration> results = [info objectForKey:ZBarReaderControllerResults];   ZBarSymbol *symbol = nil;   for(symbol in results) {     break;   }   [picker dismissViewControllerAnimated:YES completion:^{     //二维码字符串     NSString *QRCodeString = symbol.data;     // 触发回调     [self getScanDataString:QRCodeString]; }]; } /**  * 读取二维码/条码失败的回调  */ -(void)readerControllerDidFailToRead:(ZBarReaderController *)reader withRetry:(BOOL)retry{   if (retry) { //retry == 1 选择图片为非二维码。     [self dismissViewControllerAnimated:YES completion:^{       [self getScanDataString:@"未发现二维码/条码"];     }];   }   return; }</span>