可加图片二维码

#import "ViewController.h"
#import <CoreImage/CoreImage.h>

@interface ViewController ()
@property (weak, nonatomic) IBOutlet UIImageView *imageView;

@end

2.生成二维码

- (void)viewDidLoad {
    [super viewDidLoad];
    
    
}
-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
    //创建过滤器
    CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"];//CIQRCodeGenerator 不能写错
    
    //恢复默认
    [filter setDefaults];
    
    //3给过滤器添加数据
    NSString *dateString = @"12dsfae";//直接可换成网址
    NSData *data = [dateString dataUsingEncoding:NSUTF8StringEncoding];
    [filter setValue:data forKeyPath:@"inputMessage"];
    
    //4 过去输出的二维码
    CIImage *outputImage = [filter outputImage];
    
    //5显示二维码
    self.imageView.image = [self createNonInterpolatedUIImageFormCIImage:outputImage withSize:200];
}

3.清晰二维码

- (UIImage *)createNonInterpolatedUIImageFormCIImage:(CIImage *)image withSize:(CGFloat) size {
    
    CGRect extent = CGRectIntegral(image.extent);
    
    //设置比例
    
    CGFloat scale = MIN(size/CGRectGetWidth(extent), size/CGRectGetHeight(extent));
    
    // 创建bitmap（位图）;
    
    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);
    
    // 保存bitmap到图片
    
    CGImageRef scaledImage = CGBitmapContextCreateImage(bitmapRef);
    
    CGContextRelease(bitmapRef);
    
    
    
    CGImageRelease(bitmapImage);
    
    return [UIImage imageWithCGImage:scaledImage];
    
}