以下是我的模型：

class Product(models.Model):
    product_title = models.CharField(max_length=100, null=False, 
verbose_name='Product title')
    product_description = models.TextField(max_length=250, 
verbose_name='Product description')
    product_qty = models.IntegerField(verbose_name='Quantity')
    product_mrp = models.FloatField(verbose_name='Maximum retail price')
    product_offer_price = models.FloatField(verbose_name='Selling price')

def validate_produce_offer_price(sender, instance, **kwargs):
    if instance.product_offer_price > instance.product_mrp:
        from django.core.exceptions import ValidationError
        raise ValidationError('Product offer price cannot be greater than 
Product MRP.')


pre_save.connect(validate_produce_offer_price, sender=Product)

我想保存模型之前验证product_offer_price。 验证错误被成功举起，但由调试器创建的上一个异常页面。如何显示在管理本身一样由管理形式提出的其他错误表格上的错误？

models.py

from django.db import models

class Product(models.Model):
    product_title = models.CharField(max_length=100, null=False, 
verbose_name='Product title')
    product_description = models.TextField(max_length=250, 
verbose_name='Product description')
    product_qty = models.IntegerField(verbose_name='Quantity')
    product_mrp = models.FloatField(verbose_name='Maximum retail price')
    product_offer_price = models.FloatField(verbose_name='Selling price')

forms.py

from models import Product
from django import forms

class ProductForm(forms.ModelForm):
    class Meta:
        model = Product
        exclude = [id, ]

    def clean(self):
        product_offer_price = self.cleaned_data.get('product_offer_price')
        product_mrp = self.cleaned_data.get('product_mrp')
        if product_offer_price > product_mrp:
            raise forms.ValidationError("Product offer price cannot be greater than Product MRP.")
        return self.cleaned_data

admin.py

from django.contrib import admin
from forms import ProductForm
from models import Product

class ProductAdmin(admin.ModelAdmin):
    form = ProductForm
    list_display = ('product_title', 'product_description', 'product_qty', 'product_mrp', 'product_offer_price')

admin.site.register(Product, ProductAdmin)