当我尝试从表单上载图片时，一切都进行了，但图像没有保存。
有人知道为什么会这样吗？
提前感谢！

型号.py：

class Photo(models.Model):
    user = models.ForeignKey(MyUser, null=False, blank=False)
    category = models.ForeignKey("Category", default=1, null=True, blank=True)
    title = models.CharField(max_length=30, null=True, blank=True)
    description = models.TextField(max_length=120, null=True, blank=True)
    image = models.ImageField(upload_to='user/photos/', null=True, blank=True)
    slug = models.SlugField(null=True, blank=True)
    active = models.BooleanField(default=True)
    timestamp = models.DateTimeField(auto_now_add=True, auto_now=False, null=True)
    updated = models.DateTimeField(auto_now_add=False, auto_now=True, null=True)

    class Meta:
        unique_together = ('slug', 'category')
        ordering = ['-timestamp']

    def __unicode__(self):
        return "%s" %(self.user)

视图.py：

def photo_upload_view(request, username):
    u = MyUser.objects.get(username=username)

    if request.method == 'POST':
        form = PhotoUploadForm(request.POST, request.FILES)
        if form.is_valid():
            form.save()
            messages.success(request, "Thank you! You have successfully posted your picture!")
            return HttpResponseRedirect('/')
    else:
        form = PhotoUploadForm()

    submit_btn = "Upload Post"

    context = {
        "form": form,
        "submit_btn": submit_btn
    }
    return render(request, "photos/photo_upload.html", context)

表格.py：

class PhotoUploadForm(forms.ModelForm):

    class Meta:
        model = Photo
        fields = ('user', 'category', 'title', 'description', 'image')

.html文件：

<form method='POST' action='{{ action_url }}'>{% csrf_token %}
    {{ form|crispy }}
    <input class='btn btn-default {{ submit_btn_class }}' type='submit' value='{{ submit_btn }}'/>
</form>