MultipleChoiceField - invalid_choice错误 - 选择一个有效的选项。 SomeChoice不是可用选项之一

Question

我正在django中创建一个表单，希望允许用户删除他们的一些设备。当我点击我的表单的提交按钮时，我不断收到消息：Select a valid choice. <Some choice> is not one of the available choices。这是我的代码。非常感谢:)

forms.py

class DeleteDeviceForm(forms.Form): 
    devices = forms.MultipleChoiceField(widget=forms.CheckboxSelectMultiple) 

views.py

def delete_device(request): 
    if request.method == 'POST': 
     deletedeviceform = DeleteDeviceForm(request.POST) 
     if deletedeviceform.is_valid(): 
      devicelist = request.POST.getlist('devices') 
#will put other stuff there to process the data later, just want to access list now 
      return HttpResponseRedirect('/accounts/loggedin', {"devicelist": devicelist, }) 

    else: #if not a POST request 
     userid = request.user.profile.pk 
     devices = Device.objects.filter(user_id=userid) 
     deletedeviceform = DeleteDeviceForm() 
     deletedeviceform.fields['devices'].choices = [(x.id, x) for x in devices] 

    return render(request, 'userprofile/delete_device.html', {"full_name": request.user.username, "deletedeviceform": deletedeviceform,}) 

需要注意的是：我没有一个模型，这种形式

Answer 1

感谢@丹尼尔罗斯曼，我弄明白了。

这里是我改变了我的代码：

forms.py

class DeleteDeviceForm(forms.Form): 
    devices = forms.MultipleChoiceField(widget=forms.CheckboxSelectMultiple,label="Select the devices you want to delete:") 

    def __init__(self, *args, **kwargs): 
     user = kwargs.pop('user', None) 
     super(DeleteDeviceForm, self).__init__(*args, **kwargs) 
     self.fields['devices'].choices = [(x.id, x) for x in Device.objects.filter(user_id=user)] 

views.py

改变只有一条线路：

deletedeviceform = DeleteDeviceForm(request.POST, user=request.user.profile.pk) 

Answer 2

你已经设置只有GET请求上的有效选项列表。在POST上，没有选择，所以该字段永远不会有效。

该代码应该在窗体的__init__方法中进行，因此每次窗体实例化时都会运行该代码。