Django表单集管理表单发布

我知道这个问题已经被提出了很多次,我已经阅读了所有其他与这个问题有关的答案,但我仍然不知道如何使它起作用。我甚至跟着那首芭蕾舞曲( https://godjango.com/9-forms-part-4-formsets/ )在一个非常简单的形式上,但我仍然得到了这个著名的错误:

['ManagementForm data is missing or has been tampered with']

模型。py:

class InviteForm2(forms.Form):
    """
    Form for member email invite
    """
    Email = forms.EmailField(
                    widget=forms.EmailInput(attrs={
                        'placeholder': "Member's mail",
                    }),
                    required=False)

class BaseLinkFormSet(BaseFormSet):
    def clean(self):
        """
        Adds validation to check that no two links have the same anchor or URL
        and that all links have both an anchor and URL.
        """
        if any(self.errors):
            return

        Email = []
        duplicates = False

        for form in self.forms:
            if form.cleaned_data:
                email = form.cleaned_data['Email']

                # Check that no two links have the same anchor or URL
                if email:
                    if email in emails:
                        duplicates = True
                    emails.append(email)

                if duplicates:
                    raise forms.ValidationError(
                        'You cannot provide twice the same mail',
                        code='duplicate_links'
                    )

def printmail2(request):
    InviteFormSet = formset_factory(InviteForm2, formset=BaseLinkFormSet, extra=7)

    if request.method == 'POST':
        formset = InviteFormSet(request.POST, prefix='pfix')

        if(formset.is_valid()):
            for i in formset:
                a = i.value()
                print(a)
            print("success")
        else:
            print("form not valid")

    else:
        formset = InviteForm2()
    return render(request,'invite2.html',
                        {'formset':formset})

invite2.html:

{% load staticfiles %}


<h2>Form</h2>
<form method="post">
  {% csrf_token %}
  {{ formset.management_form }}

    {% for form in formset %}
    <div class="link-formset">
    <p>
      {{ form.label_tag }}{{ form }}
    </div>
        {% for error in field.errors %}
          <p style="color: red">{{ error }}</p>
        {% endfor %}
    </p>
    {% endfor %}

  <input type="submit" value="Send Invitations" class="button"/>
</form>
  <!-- Include formset plugin - including jQuery dependency -->
  <script src="//ajax.googleapis.com/ajax/libs/jquery/2.1.3/jquery.min.js"></script>
  <script src="{% static 'js/jquery.formset.js' %}"></script>
  <script>
      $('.link-formset').formset({
          addText: 'add link',
          deleteText: 'remove'
      });
  </script>