ios二維碼生成

    //創(chuàng)建濾鏡對象

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

    //恢復(fù)濾鏡的默認(rèn)屬性

    [filter setDefaults];

    NSData *infoData = [data dataUsingEncoding:NSUTF8StringEncoding];

    //設(shè)置filter的InputMessages數(shù)據(jù)

    [filter setValue:infoData forKeyPath:@"inputMessage"];

    CIImage *outputImage = [filter outputImage];

    UIImage *image = [self createUIImageFromCIImage:outputImage withWidth:width];

    return image;
}

根據(jù)CIImage生成指定大小的UIImage

+ (UIImage *)createUIImageFromCIImage:(CIImage *)CIImage withWidth:(CGFloat)imageWidth{

    CGRect extent = CGRectIntegral(CIImage.extent);
    CGFloat scale = MIN(imageWidth / CGRectGetWidth(extent), imageWidth / CGRectGetHeight(extent));
    
    //創(chuàng)建bitMap
    size_t width = CGRectGetWidth(extent) * scale;
    size_t height = CGRectGetHeight(extent) * scale;
    CGColorSpaceRef colorSpaceRef = CGColorSpaceCreateDeviceGray();
    CGContextRef bitmapRef = CGBitmapContextCreate(nil, width, height, 8, 0, colorSpaceRef, (CGBitmapInfo)kCGImageAlphaNone);
    CIContext *context = [CIContext contextWithOptions:nil];
    
    CGImageRef bitmapImage = [context createCGImage:CIImage fromRect:extent];
    CGContextSetInterpolationQuality(bitmapRef, kCGInterpolationNone);
    CGContextScaleCTM(bitmapRef, scale, scale);
    CGContextDrawImage(bitmapRef, extent, bitmapImage);
    
    CGImageRef scaledImage = CGBitmapContextCreateImage(bitmapRef);
    CGContextRelease(bitmapRef);
    CGImageRelease(bitmapImage);
    
    return [UIImage imageWithCGImage:scaledImage];
}

+ (UIImage *)generateLogoQRCode:(NSString *)data imageWidth:(CGFloat)imageWidth logoImageName:(NSString *)logoImageName logoScaleToSuperView:(CGFloat)logoScale{
    
    CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"];
    //恢復(fù)濾鏡的默認(rèn)屬性
    [filter setDefaults];
    
    NSData *infoData = [data dataUsingEncoding:NSUTF8StringEncoding];
    
    //設(shè)置filter的InputMessages數(shù)據(jù)
    [filter setValue:infoData forKeyPath:@"inputMessage"];
    CIImage *outputImage = [filter outputImage];
    
//    outputImage = [outputImage imageByApplyingTransform:CGAffineTransformMakeScale(20, 20)];
    //將CIImage轉(zhuǎn)化為UIImage類型
    UIImage *start_image = [self createUIImageFromCIImage:outputImage withWidth:imageWidth];
    
    //添加logo
    UIGraphicsBeginImageContext(start_image.size);
    [start_image drawInRect:CGRectMake(0, 0, start_image.size.width, start_image.size.height)];
    
    //畫logo
    UIImage *logoImage = [UIImage imageNamed:logoImageName];
    CGFloat logoWidth = start_image.size.width * logoScale;
    CGFloat logoHeight = start_image.size.height * logoScale;
    CGFloat logoX = (start_image.size.width - logoWidth) / 2;
    CGFloat logoY = (start_image.size.width - logoHeight) / 2;
    [logoImage drawInRect:CGRectMake(logoX, logoY, logoWidth, logoHeight)];
    
    //獲取最后的圖片
    UIImage *finalImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return finalImage;
}

掃描

掃描前需要申請調(diào)用攝像頭的權(quán)限

    AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
    //創(chuàng)建輸入流
    AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:device error:nil];
    //創(chuàng)建輸出流
    AVCaptureMetadataOutput *output = [[AVCaptureMetadataOutput alloc] init];
    //設(shè)置代理签夭，在主線程中刷新
    [output setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];
    //設(shè)置掃描范圍（取值范圍0-1，一屏幕右上角為坐標(biāo)原點(diǎn)）
    output.rectOfInterest = CGRectMake(0.2, 0.2, 0.6, 0.6);
    
    _session = [[AVCaptureSession alloc] init];
    //設(shè)置采集率
    [_session setSessionPreset:AVCaptureSessionPresetHigh];
    
    //添加會話輸入輸出
    [_session addInput:input];
    [_session addOutput:output];
    
    //設(shè)置輸出數(shù)據(jù)類型弟灼，需要將元數(shù)據(jù)輸出添加到會話中，才能指定元數(shù)據(jù)類型
    //設(shè)置掃碼支持的編碼格式
    output.metadataObjectTypes = @[AVMetadataObjectTypeQRCode,AVMetadataObjectTypeEAN8Code,AVMetadataObjectTypeEAN13Code,AVMetadataObjectTypeCode128Code];
    
    //初始化previewLayer鹤树，傳遞給session將要顯示什么
    _previewLayer = [AVCaptureVideoPreviewLayer layerWithSession:_session];
    _previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;
    _previewLayer.frame = self.view.layer.bounds;
    
    //將圖層插入當(dāng)前視圖
    [self.view.layer insertSublayer:_previewLayer atIndex:0];
    //啟動會話
    [_session startRunning];

具體代碼見GitHub：https://github.com/huyong668/HYQRCode