How to add product into shopping cart by single click using custom module in magento 2?

Question

My template file code is

$listBlock = $this->_listBlock;
     $addToCartUrl =  $listBlock->getAddToCartUrl($_product);
     ?>
     <form data-role="tocart-form" action="<?php echo $addToCartUrl; ?>" method="post"> 

    <?php echo $block->getBlockHtml('formkey')?>
    <button type="submit" title="Add to Cart" class="action tocart primary">

       <span>Add to Cart</span>
     </button>
 </form>

My Block code is

<?php
namespace Vendor\Modulename\Block;
class AddProduct extends \Magento\Framework\View\Element\Template
{

  protected $_productCollectionFactory;
   public $_listBlock;

public function __construct(
    \Magento\Framework\View\Element\Template\Context $context,

   \Magento\Catalog\Model\ResourceModel\Product\CollectionFactory $productCollectionFactory,

    \Magento\Catalog\Block\Product\ListProduct $listBlock,
    array $data = []
)
{


    $this->_productCollectionFactory = $productCollectionFactory;

    $this->_listBlock = $listBlock;

    parent::__construct($context, $data);
}
}

Answer 1

Need some change at block class

• change extends class

  \Magento\Framework\View\Element\Template

to

 \Magento\Catalog\Block\Product\AbstractProduct

Add implements class Magento\Framework\DataObject\IdentityInterface;

Add add to cart function

 public function getAddToCartPostParams(\Magento\Catalog\Model\Product $product)
    {
        $url = $this->getAddToCartUrl($product);
        return [
            'action' => $url,
            'data' => [
                'product' => $product->getEntityId(),
                \Magento\Framework\App\ActionInterface::PARAM_NAME_URL_ENCODED =>
                    $this->urlHelper->getEncodedUrl($url),
            ]
        ];
    }

• Change template file

change template to Magento_Catalog::product/list.phtml

Modified class

<?php
namespace Vendor\Modulename\Block;
/* add some class */
use Magento\Catalog\Model\Product;
use Magento\Framework\Exception\NoSuchEntityException;
use Magento\Framework\DataObject\IdentityInterface;

class AddProduct extends \Magento\Catalog\Block\Product\AbstractProduct implements IdentityInterface
{
....
 public function getAddToCartPostParams(\Magento\Catalog\Model\Product $product)
    {
        $url = $this->getAddToCartUrl($product);
        return [
            'action' => $url,
            'data' => [
                'product' => $product->getEntityId(),
                \Magento\Framework\App\ActionInterface::PARAM_NAME_URL_ENCODED =>
                    $this->urlHelper->getEncodedUrl($url),
            ]
        ];
    }

  public function getLoadedProductCollection()
    {
        return  $this->_productCollectionFactory;
    }

}