在models.py下导入
#修改和删除数据时,删除旧图片,保存新图
from django.db.models.signals import pre_delete,post_save,post_init
from django.dispatch.dispatcher import receiver
#删除时
@receiver(pre_delete, sender=Template)
def delete(sender, instance, **kwargs):
# Pass false so FileField doesn't save the model.
instance.file.delete(False)
#修改时
@receiver(post_init, sender=Template)
def file_path(sender, instance, **kwargs):
instance._current_file = instance.file
@receiver(post_save, sender= Template)
def delete_old_image(sender, instance, **kwargs):
if hasattr(instance, '_current_file'):
if instance._current_file != instance.file.path:
instance._current_file.delete(save=False)
说明:
- Template:是models下的数据库类的名称
- instance的属性file要自己修改,为models下的数据库类下的属性