ios--二维码生成

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];
}