ios原生二维码扫描与生成的实现教程

#import 

//捕获设备，默认后置摄像头
@property (strong, nonatomic) AVCaptureDevice * device;

//输入设备
@property (strong, nonatomic) AVCaptureDeviceInput * input;

//输出设备，需要指定他的输出类型及扫描范围
@property (strong, nonatomic) AVCaptureMetadataOutput * output;

//AVFoundation框架捕获类的中心枢纽，协调输入输出设备以获得数据
@property (strong, nonatomic) AVCaptureSession * session;

//展示捕获图像的图层，是CALayer的子类
@property (strong, nonatomic) AVCaptureVideoPreviewLayer * preview;

- (void)chooseButtonClick
{
if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary]) {
//关闭扫描
[self stopScan];

//1 弹出系统相册
UIImagePickerController *pickVC = [[UIImagePickerController alloc]init];
//2 设置照片来源
/**
UIImagePickerControllerSourceTypePhotoLibrary,相册
UIImagePickerControllerSourceTypeCamera,相机
UIImagePickerControllerSourceTypeSavedPhotosAlbum,照片库
*/

pickVC.sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum;
//3 设置代理
pickVC.delegate = self;
//4.转场动画
self.modalTransitiOnStyle=UIModalTransitionStyleFlipHorizontal;
[self presentViewController:pickVC animated:YES completion:nil];
}
else
{
[self showAlertViewWithTitle:@"打开失败" withMessage:@"相册打开失败。设备不支持访问相册，请在设置->隐私->照片中进行设置！"];
}

}

/**
* 2.生成CIFilter(滤镜)对象
*/
CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"];

/**
* 3.恢复滤镜默认设置
*/
[filter setDefaults];

/**
* 4.设置数据(通过滤镜对象的KVC)
*/
//存放的信息
NSString *info = @"hahahahhahahaha";
//把信息转化为NSData
NSData *infoData = [info dataUsingEncoding:NSUTF8StringEncoding];
//滤镜对象kvc存值
[filter setValue:infoData forKeyPath:@"inputMessage"];

/**
* 5.生成二维码
*/
CIImage *outImage = [filter outputImage];

//imageView.image = [UIImage imageWithCIImage:outImage];//不处理图片模糊,故而调用下面的信息

self.codeImage.image = [outImage createNonInterpolatedWithSize:150];

UIGraphicsBeginImageContext(self.view.bounds.size);
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
//获取图片
UIImage * image = UIGraphicsGetImageFromCurrentImageContext();
//关闭上下文
UIGraphicsEndImageContext();
completion(image);

/**
* 将图片保存到本地相册
*/
UIImageWriteToSavedPhotosAlbum(image, self , @selector(saveImage:didFinishSavingWithError:contextInfo:), nil);//保存图片到照片库