在django中将特定数量的产品添加到购物车

我有一个问题，因为我不知道如何实现“添加特定数量的产品到购物车”。 目前，在按下“加入购物车”按钮后，只会增加一个产品数量。 我不知道如何在视图和模板中联系起来。 我希望它取给定的值而不是1。

cart_item.quantity += 1

车/ views.py

def add_cart(request, product_id):
    product = Product.objects.get(id=product_id)
    try:
        cart = Cart.objects.get(cart_id=_cart_id(request))
    except Cart.DoesNotExist:
        cart = Cart.objects.create(
                cart_id = _cart_id(request)
            )
        cart.save()
    try:
      cart_item = CartItem.objects.get(product=product, cart=cart)
      if cart_item.quantity < cart_item.product.stock:
          cart_item.quantity += 1
      cart_item.save()
    except CartItem.DoesNotExist:
      cart_item = CartItem.objects.create(
                  product = product,
                  quantity = 1,
                  cart = cart
          )
      cart_item.save()
    return redirect('cart:cart_detail')

车/ models.py

class Cart(models.Model):
    cart_id = models.CharField(max_length=250, blank=True)
    date_added = models.DateField(auto_now_add=True)
    class Meta:
        db_table = 'Cart'
        ordering = ['date_added']

    def __str__(self):
        return self.cart_id

class CartItem(models.Model):
    product = models.ForeignKey(Product, on_delete=models.CASCADE)
    cart = models.ForeignKey(Cart, on_delete=models.CASCADE)
    quantity = models.IntegerField()
    active = models.BooleanField(default=True)
    class Meta:
        db_table = 'CartItem'

    def sub_total(self):
        return self.product.price * self.quantity

    def __str__(self):
        return self.product

模板/商店/ product.html

  <div class="float-right">
   <div class="float-left"> <input type="number" value="1" aria-label="Search" 
    class="form-control" style="width: 100px"> </div>
    <a class="btn send-click btn-md my-0 p"  href="{% url 'cart:add_cart' product.id %}">Add to Cart</a></div>

urls . py

app_name='cart'

urlpatterns = [
    path('add/<int:product_id>/', views.add_cart, name='add_cart'),
    path('', views.cart_detail, name='cart_detail'),
    path('remove/<int:product_id>/', views.cart_remove, name='cart_remove'),
    path('full_remove/<int:product_id>/', views.full_remove, name='full_remove'),
]

问题来源StackOverflow 地址：/questions/59379019/adding-a-specific-quantity-of-the-product-to-the-cart-in-django