二维码读取

来源
读取主要用到CoreImage 不过要强调的是读取二维码的功能只有在iOS8之后才支持，我们需要在相册中调用一个二维码，将其读取，代码如下

#pragma mark-> 我的相册
-(void)myAlbum{
    
    NSLog(@"我的相册");
    if([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary]){
        //1.初始化相册拾取器
        UIImagePickerController *controller = [[UIImagePickerController alloc] init];
        //2.设置代理
        controller.delegate = self;
        //3.设置资源：
        /**
         UIImagePickerControllerSourceTypePhotoLibrary,相册
         UIImagePickerControllerSourceTypeCamera,相机
         UIImagePickerControllerSourceTypeSavedPhotosAlbum,照片库
         */
        controller.sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum;
        //4.随便给他一个转场动画
        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];
    }
    
}

完成相册代理， 我们在代理中添加读取二维码方法

#pragma mark-> imagePickerController delegate
- (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;
            UIAlertView * alertView = [[UIAlertView alloc]initWithTitle:@"扫描结果" message:scannedResult delegate:nil cancelButtonTitle:@"确定" otherButtonTitles:nil, nil];
            [alertView show];
          
        }
        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];
            
        }
        
  
    }];
    
    
}