iOS功能 - 根据链接生成二维码图片（高清）
根据链接生成高清二维码
1 - 代码示例
1 -(void)generatingTwoDimensionalCode { 2 3 // 过滤器 4 CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"]; 5 6 // 默认 7 [filter setDefaults]; 8 9 // 给过滤器添加数据 10 NSString *string = @"https://www.baidu.com"; // 以百度为例 11 NSData *data = [string dataUsingEncoding:NSUTF8StringEncoding allowLossyConversion:YES]; 12 13 [filter setValue:data forKeyPath:@"inputMessage"]; 14 15 // 获取二维码过滤器生成的二维码 16 CIImage *image = [filter outputImage];// 该时 image 是模糊的 17 18 // 高清处理：将获取到的二维码添加到 imageview 19 self.imageView.image =[self createNonInterpolatedUIImageFormCIImage:image withSize:300];// withSize 大于等于视图将要显示的尺寸 20 } 21 22 // 高清二维码 23 - (UIImage *)createNonInterpolatedUIImageFormCIImage:(CIImage *)image withSize:(CGFloat) size { 24 25 CGRect extent = CGRectIntegral(image.extent); 26 CGFloat scale = MIN(size/CGRectGetWidth(extent), size/CGRectGetHeight(extent)); 27 28 // 创建 bitmap 29 size_t width = CGRectGetWidth(extent) * scale; 30 size_t height = CGRectGetHeight(extent) * scale; 31 CGColorSpaceRef cs = CGColorSpaceCreateDeviceGray(); 32 CGContextRef bitmapRef = CGBitmapContextCreate(nil, width, height, 8, 0, cs, (CGBitmapInfo)kCGImageAlphaNone); 33 CIContext *context = [CIContext contextWithOptions:nil]; 34 CGImageRef bitmapImage = [context createCGImage:image fromRect:extent]; 35 CGContextSetInterpolationQuality(bitmapRef, kCGInterpolationNone); 36 CGContextScaleCTM(bitmapRef, scale, scale); 37 CGContextDrawImage(bitmapRef, extent, bitmapImage); 38 39 // 保存 bitmap 到图片 40 CGImageRef scaledImage = CGBitmapContextCreateImage(bitmapRef); 41 CGContextRelease(bitmapRef); 42 CGImageRelease(bitmapImage); 43 return [UIImage imageWithCGImage:scaledImage]; 44 }
