覆盖保存方法 - “ImageFile”对象没有属性“_commissed”

我重写了保存方法，如下所示，并使用 get_thumbnails 和 sorl 保存..

但得到错误'ImageFile' object has no attribute '_committed'

class HotelPhotos(models.Model):
    hotel = models.ForeignKey(Hotel, related_name='photos')
    code = models.CharField(max_length=255)
    original = models.ImageField(upload_to="media")
    medium = models.ImageField(upload_to="media", null=True, editable=False)
    thumbnail = models.ImageField(upload_to="media", null=True, editable=False)

    def save(self, *args, **kwargs):

        super(HotelPhotos, self).save(*args, **kwargs)
        self.medium = get_thumbnail(self.original,
                                    '100x100',
                                    crop='center',
                                    quality=99)

        self.thumbnail = get_thumbnail(self.original,
                                       '50x50',
                                       crop='center',
                                       quality=99)

        super(HotelPhotos, self).save(*args, **kwargs)

有任何想法吗 ？

self.thumbnail = get_thumbnail(self.original,
                                   '50x50',
                                   crop='center',
                                   quality=99).url

解决了我的问题..