如何在UpdateView post方法中手动更新外键字段？

from django.views.generic.edit import UpdateView
from .models import YourModel
from .forms import YourForm

class YourUpdateView(UpdateView):
    model = YourModel
    form_class = YourForm
    template_name = 'your_template.html'
    success_url = '/success_url/'

    def post(self, request, *args, **kwargs):
        response = super().post(request, *args, **kwargs)

        # 获取外键字段的值
        foreign_key_value = request.POST.get('foreign_key_field')

        # 更新外键字段
        self.object.foreign_key_field = foreign_key_value
        self.object.save()

        return response