更换django自带的下载链接

 class Case(models.Model):
     file_type = MyFileField(verbose_name='file_obj', max_length=256, blank=True, null=True)
     link = models.CharField(verbose_name='下载链接', max_length=64, blank=True, null=True)

     def __unicode__(self):
         return u"%s" % self.file_type.name

 class MyFileField(models.FileField):
     attr_class = MyFieldFile

 class MyFieldFile(FieldFile):

     def __init__(self, *args, **kwargs):
         super(MyFieldFile, self).__init__(*args, **kwargs)

     @property
     def url(self):
         return self.instance.link

filefiled