AVFoundation 从相册中读取二维码

1、例如在我们的导航栏中设置一个按钮

-(void)setupRightMenuButton{
    self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc]initWithTitle:@"相册中选" style:UIBarButtonItemStylePlain target:self action:@selector(takeQRCodeFromPic)];
}

2、初始化相册拾取器

-(void)takeQRCodeFromPic{

    if([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary]){
        UIImagePickerController *controller = [[UIImagePickerController alloc] init];
        controller.delegate = self;
        controller.sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum;
        controller.modalTransitionStyle=UIModalTransitionStyleFlipHorizontal;
        [self presentViewController:controller animated:YES completion:NULL];
        
    }else{
        
        UIAlertView * alert = [[UIAlertView alloc]initWithTitle:@"提示" message:@"设备不支持访问相册，请在设置->隐私->照片中进行设置！" delegate:nil cancelButtonTitle:@"确定" otherButtonTitles:nil, nil];
        [alert show];
    }
    
}

3、实现选中照片之后的代理事件，并将图片数据进行转码扫描

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    //1.获取选择的图片
    UIImage *image = info[UIImagePickerControllerOriginalImage];
    //2.初始化一个监测器
    CIDetector*detector = [CIDetector detectorOfType:CIDetectorTypeQRCode context:nil options:@{ CIDetectorAccuracy : CIDetectorAccuracyHigh }];
    
    [picker dismissViewControllerAnimated:YES completion:^{
        //监测到的结果数组
        NSArray *features = [detector featuresInImage:[CIImage imageWithCGImage:image.CGImage]];
        if (features.count >=1) {
            /**结果对象 */
            CIQRCodeFeature *feature = [features objectAtIndex:0];
            NSString *scannedResult = feature.messageString;
            RxWebViewController* webViewController = [[RxWebViewController alloc] initWithUrl:[NSURL URLWithString:scannedResult]];
            webViewController.navigationItem.hidesBackButton = YES;
            [self.navigationController pushViewController:webViewController animated:YES];
            
        }
        else{
            UIAlertView * alertView = [[UIAlertView alloc]initWithTitle:@"提示" message:@"该图片没有包含一个二维码！" delegate:nil cancelButtonTitle:@"确定" otherButtonTitles:nil, nil];
            [alertView show];
            
        }
        
        
    }];
}