iOS7后 苹果 二维码生成与扫描

Posted 2020-07-25

 

本文是查阅网上资料和demo后整理出来的, 为了日后查阅以及其他人需要只用
之前使用的是第三方库, 最近听说ios7后, 苹果原生的二维码扫描功能效率更高, 于是学习了一下, 顺便也把生成加上.

/**

 *  打开二维码 扫描

 */

-(void)openCaptureMetada{

 

    // Do any additional setup after loading the view, typically from a nib.

    //获取摄像设备

    AVCaptureDevice * device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];

    

    //创建输入流

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

    //创建输出流

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

    if(!device)

    {

        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"提示" message:@"获取设备失败" delegate:nil cancelButtonTitle:@"确定" otherButtonTitles:nil, nil];

        [alert show];

        return;

    }

    //设置代理 在主线程里刷新

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

    

    //初始化链接对象

    session = [[AVCaptureSession alloc]init];

    //高质量采集率

    [session setSessionPreset:AVCaptureSessionPresetHigh];

    

    [session addInput:input];

    [session addOutput:output];

    

    //设置扫码支持的编码格式(如下设置条形码和二维码兼容)

    output.metadataObjectTypes=@[AVMetadataObjectTypeQRCode,AVMetadataObjectTypeEAN13Code, AVMetadataObjectTypeEAN8Code, AVMetadataObjectTypeCode128Code];

    

    // 扫描区域为屏幕坐标的(50,100,200,200)

    output.rectOfInterest = CGRectMake(100.f/screenHeight, 50.f/screenWidth, 200.f/screenHeight, 200.f/screenWidth);

    

    AVCaptureVideoPreviewLayer * layer = [AVCaptureVideoPreviewLayer layerWithSession:session];

    layer.videoGravity=AVLayerVideoGravityResizeAspectFill;

    layer.frame=self.view.layer.bounds;

    [self.view.layer insertSublayer:layer atIndex:0];

    //开始捕获

    [session startRunning];

 

}

 

 

//// 是否有相机及后置镜头

//- (BOOL)validateCamera {

//    return [UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera] &&

//    [UIImagePickerController isCameraDeviceAvailable:UIImagePickerControllerCameraDeviceRear];

//}

 

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

    if (metadataObjects.count>0) {

        //[session stopRunning];

        AVMetadataMachineReadableCodeObject * metadataObject = [metadataObjects objectAtIndex : 0 ];

        //输出扫描字符串

        NSLog(@"%@",metadataObject.stringValue);

        [session stopRunning];

    }

}

 

 

 

 

#pragma mark---- 生成二维码

/**

 *  转换 CIImage

 *

 *  @param string 生成二维码的内容

 *

 *  @return CIImage

 */

- (CIImage *)createTWMForString:(NSString *)string {

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

    // 内容

    [ewmFilter setValue:[string dataUsingEncoding:NSUTF8StringEncoding] forKey:@"inputMessage"];

    // 纠错级别

    [ewmFilter setValue:@"M" forKey:@"inputCorrectionLevel"];

    

    

    return ewmFilter.outputImage;

}

 

/**

 *   CIImage 转换 UIImageView

 *

 *  @param image CIImage

 *  @param size  决定了图片的大小

 *

 *  @return UIImageView.frame相同, size越大, 二维码图片越清晰

 */

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

    // 位图

    CGRect extent = CGRectIntegral(image.extent);

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

    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);

    // 保存bitmap到图片

    CGImageRef scaledImage = CGBitmapContextCreateImage(bitmapRef);

    CGContextRelease(bitmapRef);

    CGImageRelease(bitmapImage);

    return [UIImage imageWithCGImage:scaledImage];

}

 

void ProviderReleaseData (void *info, const void *data, size_t size) {

    free((void*)data);

}

 

 

/**

 *  // 1.更改二维码颜色

 *

 *  @param image

 *  UIImage及颜色传入这个方法, 用新生成的UIImage赋给ImageView.image.

 *   注意 ：imageView.contentMode = UIViewContentModeScaleAspectFit

 *

 */

 

- (UIImage*)imageBlackToTransparent:(UIImage*)image withRed:(CGFloat)red andGreen:(CGFloat)green andBlue:(CGFloat)blue {

    const int imageWidth = image.size.width;

    const int imageHeight = image.size.height;

    size_t bytesPerRow = imageWidth * 4;

    uint32_t *rgbImageBuf = (uint32_t *)malloc(bytesPerRow * imageHeight);

    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();

    CGContextRef context = CGBitmapContextCreate(rgbImageBuf, imageWidth, imageHeight, 8, bytesPerRow, colorSpace, kCGBitmapByteOrder32Little | kCGImageAlphaNoneSkipLast);

    CGContextDrawImage(context, CGRectMake(0, 0, imageWidth, imageHeight), image.CGImage);

    int pixelNum = imageWidth * imageHeight;

    uint32_t *pCurPtr = rgbImageBuf;

    for (int i = 0; i < pixelNum; i++, pCurPtr++) {

        if ((*pCurPtr & 0xFFFFFF00) < 0x99999900) {

            // 改成下面的代码，会将图片转成想要的颜色

            uint8_t *ptr = (uint8_t *)pCurPtr;

            ptr[3] = red; //0~255

            ptr[2] = green;

            ptr[1] = blue;

        }

        else {

            uint8_t *ptr = (uint8_t *)pCurPtr;

            ptr[0] = 0;

        }

    }

    CGDataProviderRef dataProvider = CGDataProviderCreateWithData(NULL, rgbImageBuf, bytesPerRow * imageHeight, ProviderReleaseData);

    CGImageRef imageRef = CGImageCreate(imageWidth, imageHeight, 8, 32, bytesPerRow, colorSpace, kCGImageAlphaLast | kCGBitmapByteOrder32Little, dataProvider, NULL, true, kCGRenderingIntentDefault);

    CGDataProviderRelease(dataProvider);

    UIImage *resultUIImage = [UIImage imageWithCGImage:imageRef];

    CGImageRelease(imageRef);

    CGContextRelease(context);

    CGColorSpaceRelease(colorSpace);

    return resultUIImage;

}