一、导入头文件
#import<CoreImage/CoreImage.h>
二、生成二维码
- (UIImage *)createQRCodeWithUrl:(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 drawImage:QLNamedImage(@"qr_logo") inImage:qrcode];
return qrcode;
}
三、将二维码转成高清模式
- (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];
}
四、添加logo
- (UIImage *)drawImage:(UIImage *)newImage inImage:(UIImage *)sourceImage {
CGSize imageSize; //画的背景 大小
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;
}
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