二维码

1.二维码生成

#import

@property (weak, nonatomic) IBOutlet UIImageView *QRCImage;

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event

{

    // 1.创建滤镜

    CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"];

    

    // 2.清空滤镜(还原默认设置, 因为滤镜有可能保存上一次的设置)

    [filter setDefaults];

    

    // 3.创建二维码需要保存的数据

    NSData *data = [@"IOS开发很牛逼" dataUsingEncoding:NSUTF8StringEncoding];

    

    // 4.设置数据(KVC)

    [filter setValue:data forKey:@"inputMessage"];

    

    // 5.生成二维码, 获取生成后的二维码图片

    CIImage *image = [filter outputImage];

    

    // 7.设置图片到容器上

    

    self.QRCImage.image = [self createNonInterpolatedUIImageFormCIImage:image withSize:400];

}

//  根据CIImage生成指定大小的UIImage

//  @param image CIImage

//  @param size  图片宽度

- (UIImage *)createNonInterpolatedUIImageFormCIImage:(CIImage *)image withSize:(CGFloat) size

{

    CGRect extent = CGRectIntegral(image.extent);

    CGFloat scale = MIN(size/CGRectGetWidth(extent), size/CGRectGetHeight(extent));

    // 1.创建bitmap;

    size_t width = CGRectGetWidth(extent) * scale;

    size_t height = CGRectGetHeight(extent) * scale;

    CGColorSpaceRef cs = CGColorSpaceCreateDeviceGray();

    CGContextRef bitmapRef = CGBitmapContextCreate(nil, width, height, 8, 0, cs, (CGBitmapInfo)kCGImageAlphaNone);

    CIContext *context = [CIContext contextWithOptions:nil];

    CGImageRef bitmapImage = [context createCGImage:image fromRect:extent];

    CGContextSetInterpolationQuality(bitmapRef, kCGInterpolationNone);

    CGContextScaleCTM(bitmapRef, scale, scale);

    CGContextDrawImage(bitmapRef, extent, bitmapImage);

    // 2.保存bitmap到图片

    CGImageRef scaledImage = CGBitmapContextCreateImage(bitmapRef);

    CGContextRelease(bitmapRef);

    CGImageRelease(bitmapImage);

    return [UIImage imageWithCGImage:scaledImage];

}

 

2.二维码扫描

#import

@interface ViewController ()

@property(nonatomic,strong)AVCaptureSession *session;

@property(nonatomic,weak)AVCaptureVideoPreviewLayer *previeviewLayer;

@end

@implementation ViewController

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event

{

    

    // 1.获取输入设备(IOS中的输入设备: 摄像头.麦克风)

    AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];

    // 2.根据输入设备创建输入对象

    AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:device error:NULL];

    

    

    // 3.创建输出对象

    AVCaptureMetadataOutput *output = [[AVCaptureMetadataOutput alloc] init];

    // 4.设置数据对象的代理

    [output setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];

    

    // 5.创建会话

    AVCaptureSession *session = [[AVCaptureSession alloc] init];

    self.session = session;

    

    // 6.将输入对象添加到会话中

    if ([session canAddInput:input]) {

        [session addInput:input];

    }

    // 7.将输出对象添加到会话中

    if ([session canAddOutput:output]) {

        [session addOutput:output];

    }

    

    // 8.设置输出数据的类型

    [output setMetadataObjectTypes:@[AVMetadataObjectTypeQRCode]];

    

    

    // 9.设置预览界面

    AVCaptureVideoPreviewLayer *previeviewLayer = [AVCaptureVideoPreviewLayer layerWithSession:session];

    previeviewLayer.frame = self.view.bounds;

    [self.view.layer addSublayer:previeviewLayer];

    self.previeviewLayer = previeviewLayer;

    

    // 10.开始扫描

    [session startRunning];

}

#pragma mark - AVCaptureMetadataOutputObjectsDelegate

// 只要获取到扫描的数据就会调用

- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection

{

    

    // 1.停止扫描

    [self.session stopRunning];

    

    // 2.移除预览界面

    [self.previeviewLayer removeFromSuperlayer];

    

    // 3.取出获取到的数据显示到界面上

    UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 300, 300)];

    label.backgroundColor = [UIColor redColor];

    [self.view addSubview:label];

    

    // 3.1从元数据中取出扫描到的数据

   AVMetadataMachineReadableCodeObject *object = [metadataObjects lastObject];

    // 3.1从从元数据中取出字符串

    label.text = object.stringValue;

}

@end