OC生成二维码

1.先 #import <CoreImage/CoreImage.h>

 

2.  //本地生成二维码

    // 1.创建过滤器 -- 苹果没有将这个字符封装成常量

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

    // 2.过滤器恢复默认设置

    [filter setDefaults];

    // 3.给过滤器添加数据(正则表达式/帐号和密码) -- 通过KVC设置过滤器,只能设置NSData类型

    NSString *dataString = @"www.baidu.com";

    NSData *data = [dataString dataUsingEncoding:NSUTF8StringEncoding];

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

    // 4.获取输出的二维码

    CIImage *outputImage = [filter outputImage];

   

    self.CodeImageView.image = [UIImage imageWithCIImage:outputImage];

    self.QRCodeImageView.image = [self createNonInterpolatedUIImageFormCIImage:outputImage withSize:200];

 

3、

/重绘输出的二维码名片，使其更清晰

- (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];

}

 

来源：https://www.cnblogs.com/-ios/p/9592614.html