iOS - 长按图片识别图中二维码

长按图片识别图中二维码：

 // 长按图片识别二维码 
 
     UILongPressGestureRecognizer *QrCodeTap = [[UILongPressGestureRecognizer alloc]initWithTarget:self action:@selector(QrCodeClick:)];
 
     [self.view addGestureRecognizer:QrCodeTap];
 
 - (void)QrCodeClick:(UILongPressGestureRecognizer *)pressSender {
 
     if (pressSender.state != UIGestureRecognizerStateBegan) {
 
         return;//长按手势只会响应一次
 
     }
 
 //    MJPhoto *photo = _photos[_currentPhotoIndex];
 
     //截图 再读取
 
     //第一个参数表示区域大小。第二个参数表示是否是非透明的。如果需要显示半透明效果，需要传NO，否则传YES。第三个参数就是屏幕密度了,获取当前屏幕分辨率[UIScreen mainScreen].scale
 
     UIGraphicsBeginImageContextWithOptions(self.view.bounds.size, YES, 2.2);
 
     CGContextRef context = UIGraphicsGetCurrentContext();
 
     [self.view.layer renderInContext:context];
 
     UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
 
     UIGraphicsEndImageContext();
 
     CIImage *ciImage = [[CIImage alloc] initWithCGImage:image.CGImage options:nil];
 
     CIContext *ciContext = [CIContext contextWithOptions:@{kCIContextUseSoftwareRenderer : @(YES)}]; // 软件渲染
 
     CIDetector *detector = [CIDetector detectorOfType:CIDetectorTypeQRCode context:ciContext options:@{CIDetectorAccuracy : CIDetectorAccuracyHigh}];// 二维码识别
 
     NSArray *features = [detector featuresInImage:ciImage];
 
     if (features.count) {
 
         for (CIQRCodeFeature *feature in features) {
 
             NSLog(@"qrCodeUrl = %@",feature.messageString); // 打印二维码中的信息
 
             qrCodeUrl = feature.messageString;
 
         }
 
         // 初始化弹框 第一个参数是设置距离底部的边距
 
         alertview = [[RomAlertView alloc] initWithMainAlertViewBottomInset: Title:nil detailText:nil cancelTitle:nil otherTitles:[NSMutableArray arrayWithObjects:@"保存图片",@"识别图中二维码",nil]];
 
         alertview.tag = ;
 
         // 设置弹框的样式
 
         alertview.RomMode = RomAlertViewModeBottomTableView;
 
         // 设置弹框从什么位置进入 当然也可以设置什么位置退出
 
         [alertview setEnterMode:RomAlertEnterModeBottom];
 
         // 设置代理
 
         [alertview setDelegate:self];
 
         // 显示 必须调用 和系统一样
 
         [alertview show];
 
     } else {
 
         NSLog(@"图片中没有二维码");
 
     }
 
 }
 
 #pragma mark -- RomAlertViewDelegate 弹框识别图中二维码
 
 - (void)alertview:(RomAlertView *)alertview didSelectRowAtIndexPath:(NSIndexPath *)indexPath
 
 {
 
     if (alertview.tag == ) {
 
         if ([alertview.otherTitles[indexPath.row]  isEqualToString:@"保存图片"]) {
 
             NSLog(@"保存图片");
 
             [self saveButtonPressed];
 
         }else if ([alertview.otherTitles[indexPath.row] isEqualToString:@"识别图中二维码"]){
 
             NSLog(@"识别图中二维码");
 
             // 隐藏
 
             [alertview hide];
 
             [self leftBackButtonPressed];
 
             AppDelegate *delegate=(AppDelegate *)[[UIApplication sharedApplication]delegate];
 
             if([delegate.window.rootViewController isKindOfClass:[UITabBarController class]]){
 
                 UITabBarController *tabBarController = (UITabBarController *)delegate.window.rootViewController;
 
                 UINavigationController *navigationController = [tabBarController selectedViewController];
 
                 UIViewController *vc = navigationController.topViewController;
 
                 //对结果进行处理跳转网页
 
                 ADWebViewViewController *controller = [[ADWebViewViewController alloc] init];
 
                 controller.m_url = qrCodeUrl;
 
                 controller.hidesBottomBarWhenPushed = YES;
 
                 [vc.navigationController pushViewController:controller animated:YES];
 
             }
 
         }
 
     }
 
 }