二维码扫描

• 使用ios的CIFilter框架实现二维码生成

//生成二维码-(void)setupScan{    CIFilter *filter=[CIFilter filterWithName:@"CIQRCodeGenerator"];    [filter setDefaults];    NSString *urlstr=@"http://www.ychpay.com/down.html";    NSData *data=[urlstr dataUsingEncoding:NSUTF8StringEncoding];    [filter setValue:data forKey:@"inputMessage"];    CIImage *outputImage=[filter outputImage];    UIImageView *wechatImageView=[[UIImageView alloc]initWithFrame:CGRectMake(0, 0, 100, 100)];    wechatImageView.image=[self createNonInterpolatedUIImageFormCIImage:outputImage withSize:200];    [self.view addSubview:wechatImageView];    }- (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];}