Django:如何从产品模型显示ProductImage

class Product(models.Model):
    company = models.ForeignKey('Company', on_delete=models.SET_NULL, null=True)

class ProductImage(models.Model):
    product = models.ForeignKey('Product', on_delete=models.SET_NULL, null=True)
    image_path = models.ImageField(max_length=255,null=True,blank=True,upload_to='images/%Y/%m/%d')

在我看来。py公司

class HomeView(ListView):
    template_name = "catalog/product_list.html"
    context_object_name = 'product_list'
    model = Product

在product\u列表中。html问题就在这里

{% if product_list %}           
    {% for product in product_list %}
         <!-- the problem is here -->
         if there is an image show 
         <img src="default" />
         else
         <img src="product.ProductImage.image_path here" />
    {% endfor %}
{% endif %}  

问题出在product\u列表的迭代中 我试过了,productImage=产品。[productImage或product\u image或它是productImage]。first()但它不起作用

我也试过了

{% 
                            img = ''
                            try:
                                productImage = product.productimage_set.first() 
                                img = productImage.image_path
                            except ProductImage.DoesNotExist:   
                                img = ''
                                %}
                                <img class="card-img-top" style="height: 225px; width: 100%; display: block;" src="{{product_image.image_path}}" data-holder-rendered="true">
                                {%
                            %}

但它只输出代码块

我也试过这个

 {% productImage = product.productimage_set.first() %}

但上面说 “productImage”,应为“empty”或“endfor”。您是否忘记注册或加载此标签?