/**
* 生成二维码
*/
+ (UIImage *)creatCIQRCodeImage:(NSString *)dataStr{
//创建过滤器,这里的@"CIQRCodeGenerator"是固定的
CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"];
//恢复默认设置
[filter setDefaults];
//给过滤器添加数据
NSData *data = [dataStr dataUsingEncoding:NSUTF8StringEncoding];
//value必须是NSData类型
[filter setValue:data forKeyPath:@"inputMessage"];
//生成二维码
CIImage *outputImage = [filter outputImage];
//显示二维码
return [self creatNonInterpolatedUIImageFormCIImage:outputImage withSize:100.0];
}
+ (UIImage *)creatNonInterpolatedUIImageFormCIImage:(CIImage *)image withSize:(CGFloat)size {
CGRect extent = CGRectIntegral(image.extent);
CGFloat scale = MIN(size/CGRectGetWidth(extent), size/CGRectGetHeight(extent));
//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);
//保存bitmap图片
CGImageRef scaledImage = CGBitmapContextCreateImage(bitmapRef);
CGContextRelease(bitmapRef);
CGImageRelease(bitmapImage);
return [UIImage imageWithCGImage:scaledImage];
}
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