oc 生成高清二维码

QRCodeImageObj.h

@interface QRCodeImageObj : NSObject

///文字生成二维码图片
- (UIImage *)extCreateQRCodeWithUrl:(NSString *)url;
/// 添加logo, 将newImage添加到sourceImage，位置居中
- (UIImage *)extAddLogoImage:(UIImage *)newImage onImage:(UIImage *)sourceImage;
///保存到相册
- (void)extSave2AlbumWithImage:(UIImage *)image;

@end

QRCodeImageObj.m

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

@implementation QRCodeImageObj

///文字生成二维码图片
- (UIImage *)extCreateQRCodeWithUrl:(NSString *)url {
    // 1. 创建一个二维码滤镜实例(CIFilter)
    CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"];
    // 滤镜恢复默认设置
    [filter setDefaults];
    
    // 2. 给滤镜添加数据
    NSString *string = url;
    NSData *data = [string dataUsingEncoding:NSUTF8StringEncoding];
    // 使用KVC的方式给filter赋值
    [filter setValue:data forKeyPath:@"inputMessage"];
    
    // 3. 生成二维码
    CIImage *image = [filter outputImage];
    // 转成高清格式
    UIImage *qrcode = [self createNonInterpolatedUIImageFormCIImage:image withSize:200];
    // 添加logo
    qrcode = [self extAddLogoImage:[UIImage imageNamed:@"icon"] onImage:qrcode];
    return qrcode;
}

/// 将二维码转成高清的格式
- (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];
}

/// 添加logo, 将newImage添加到sourceImage，位置居中
- (UIImage *)extAddLogoImage:(UIImage *)newImage onImage:(UIImage *)sourceImage {
    
    //画的背景 大小
    CGSize imageSize = [sourceImage size];
    UIGraphicsBeginImageContextWithOptions(imageSize, NO, 0.0);
    
    [sourceImage drawAtPoint:CGPointMake(0, 0)];
    
    //获得 图形上下文
    CGContextRef context = UIGraphicsGetCurrentContext();
    //画 自己想要画的内容(添加的图片)
    CGContextDrawPath(context, kCGPathStroke);
    // 注意logo的尺寸不要太大,否则可能无法识别
    CGRect rect = CGRectMake(imageSize.width / 2 - 25, imageSize.height / 2 - 25, 50, 50);
//    CGContextAddEllipseInRect(context, rect);
    CGContextClip(context);
    
    [newImage drawInRect:rect];
    
    //返回绘制的新图形
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return image;
}

- (void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo {
    NSLog(@"%@ err:%@", NSStringFromSelector(_cmd), error.description);
}

///保存到相册
- (void)extSave2AlbumWithImage:(UIImage *)image {
    if (nil == image) {
        return;
    }
    
    UIImageWriteToSavedPhotosAlbum(image, self, @selector(image:didFinishSavingWithError:contextInfo:), NULL);
}

- (void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo {
    NSLog(@"%@ err:%@", NSStringFromSelector(_cmd), error.description);
}
@end

demo

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    
    QRCodeImageObj *obj = [[QRCodeImageObj alloc] init];
    self.ivCode.image = [obj extCreateQRCodeWithUrl:@"abc"];
}