UIImage修改Size

#pragma mark - 按比例缩放图片

- (UIImage *)changeSizeWithImage:(UIImage *)image{

float enlargeFactor = image.size.width/(float)image.size.height;

CGSize size = CGSizeMake(self.height*enlargeFactor, self.height);

UIGraphicsBeginImageContext(size);

[image drawInRect:CGRectMake(0, 0, size.width, size.height)];

UIImage *scaledImage = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

NSLog(@"%f,%f",scaledImage.size.width,scaledImage.size.height);

return scaledImage;

}