Question

我的观点是这样的

class RecordView(View):
    record_form = RecordForm
    record_files = {}
    templare = 'acquisition.html'

    def get(self, request, *args, **kwargs):
        fil = urllib.urlopen('/home/student/wwww.jpg')
        self.record_files = {'small_cover': SimpleUploadedFile('hehe.jpg', fil.read())}
        rr_form = self.record_form()
        return render(request, self.template_name, {'rr_form': rr_form,
                                            })
    def post(self, request, *args, **kwargs):
        record = RecordForm(request.POST, self.record_files)
        record.save()
        HttpResponseRedirect('/')

这里我已经在get方法中填充了self.record_files ..但是在我发布数据后，我将self.record_files视为空字典。我在这里感到困惑。我该怎么办呢。

Answer 1

在get和post之间不维护视图实例的状态，因此在实例上设置record_files将不会保留它以用于下一个请求。您需要将该逻辑放在dispatch方法中，或将信息存储在用户的session中。

class RecordView(View):
    record_form = RecordForm
    record_files = {}
    templare = 'acquisition.html'

    # dispatch is called before deciding whether to use get() or post()
    # so any instance-level properties that require the request can go here.
    # This could even go in __init__().
    def dispatch(self, request, *args, **kwargs):
        fil = urllib.urlopen('/home/student/wwww.jpg')
        self.record_files = {'small_cover': SimpleUploadedFile('hehe.jpg', fil.read())}
        return super(RecordView, self).dispatch(request, *args, **kwargs)

    def get(self, request, *args, **kwargs):
        rr_form = self.record_form()
        return render(request, self.template_name, {'rr_form': rr_form,
                                        })

    # self.record_files will be available in a get, or a post (or any valid 
    # method for that matter).
    def post(self, request, *args, **kwargs):
        record = RecordForm(request.POST, self.record_files)
        record.save()
        return HttpResponseRedirect('/')

Answer 2

这正是它的假设。每当你有一个GET请求时，它会调用方法get，如果它是一个POST请求，它自然会调用post方法，而不是get方法。所以这就是你如何解决问题：

from django.views.generic import TemplateView

class RecordView(TemplateView):
    record_form = RecordForm
    record_files = {}
    template_name = 'acquisition.html'

    def get_context_data(self, **context):
        fil = urllib.urlopen('/home/student/wwww.jpg')
        self.record_files = {
            'small_cover': SimpleUploadedFile('hehe.jpg', fil.read())
        }
        context.update({
            'record_files': self.record_files,
            'rr_form': self.record_form()
        })
        fil.close()
        return super(RecordView, self).get_context_data(**context)

    def post(self, request, *args, **kwargs):
        context = self.get_context_data()
        record_form = self.record_form(request.POST, self.record_files)
        if record_form.is_valid():
             record_form.save()
        ## or do a redirect instead, like you had before:
        # return HttpResponseRedirect('/')
        context['rr_form'] = record_form
        return self.render_to_response(context)

django无法在基于类的视图中使用全局变量

2 个答案: