IOS 二维码的生成

UIImageView *twoDCodeImg;

- (void)viewDidLoad {

  //创建二维码图片

    [self creatTwoDCodeImg];

    

    //生成二维码

    [self createTwoCode];

}

#pragma mark 创建二维码图片

-(void)creatTwoDCodeImg{

    twoDCodeImg = [[UIImageView alloc] init];

    [self.view addSubview:twoDCodeImg];

    [twoDCodeImg mas_makeConstraints:^(MASConstraintMaker *make) {

        make.left.top.equalTo(self.view).offset(320);

        make.right.bottom.equalTo(self.view).offset(-0);

    }];

    twoDCodeImg.contentMode = UIViewContentModeScaleAspectFit;

}

#pragma mark 生成二维码

- (void)createTwoCode{

    NSString *aaStr=@"123";

    NSString *bbStr=@"456";

    

    // 二维码的生成

    // 1、创建过滤器

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

    // 2、恢复滤镜的默认属性

    [filter setDefaults];

    // 3、设置内容，并采用base64加密

//    NSString *str = [[NSString stringWithFormat:@"%@,%@", self.data.cId, [UserInfo uid]] base64EncodedString];

    NSString *str = [[NSString stringWithFormat:@"%@,%@", aaStr, bbStr] base64EncodedString];

    NSData *data = [str dataUsingEncoding:NSUTF8StringEncoding];

    // 使用KVO设置属性

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

    // 4、获取输出文件

    CIImage *outputImage = [filter outputImage];

    // 5、显示二维码

    CGFloat size = CGRectGetWidth(self.view.frame)-120;

    //6、设置二维码的清晰度

    twoDCodeImg.image = [self createNonInterpolatedUIImageFormCIImage:outputImage withSize:size];

}

#pragma mark 设置二维码的清晰度

- (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];

}