#pragma mark -- 生成二维码
+ (instancetype)creatImageWithQrCodeText:(NSString *)qrT WithCreatSize:(CGFloat)size{
CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"];
[filter setDefaults];
NSData *filterData = [qrT dataUsingEncoding:NSUTF8StringEncoding];
[filter setValue:filterData forKeyPath:@"inputMessage"];
CIImage *outPutImage = [filter outputImage];
return [self filterTheQrCode:outPutImage WithSize:size];
}
+ (UIImage *)filterTheQrCode:(CIImage *)ciImage WithSize:(CGFloat)size{
CGRect extent = CGRectIntegral(ciImage.extent);//获取图片的规格
CGFloat imageWidth = CGRectGetWidth(extent);
CGFloat imageHeight = CGRectGetHeight(extent);
CGFloat scale = MIN(size/imageWidth, size/imageHeight);//计算像素比例
size_t width = imageWidth*scale;
size_t height = imageHeight*scale;
CGColorSpaceRef csr = CGColorSpaceCreateDeviceGray();//创建一个颜色空间
CGContextRef bitMapRef = CGBitmapContextCreate(nil, width, height, 8, 0, csr, kCGImageAlphaNone);//绘制空间的规格
CIContext *context = [CIContext contextWithOptions:nil];//获取创建的颜色空间
CGImageRef bitmapImage = [context createCGImage:ciImage fromRect:extent];//获取要编辑的过滤图
CGContextSetInterpolationQuality(bitMapRef, kCGInterpolationNone);//连接颜色空间，CGInterpolationQuality表示插入的方式
CGContextScaleCTM(bitMapRef, scale, scale);//更改过滤图的坐标
CGContextDrawImage(bitMapRef, extent, bitmapImage);//重新绘制过滤图
// 2.保存bitmap到图片
CGImageRef scaledImage = CGBitmapContextCreateImage(bitMapRef);//按照绘制空间的规格生成新图片
CGContextRelease(bitMapRef);
CGImageRelease(bitmapImage);
return [UIImage imageWithCGImage:scaledImage];
}
