Magento2: Programatically update cart via event

Question

After controller_action_predispatch_checkout_cart_index event dispatcher i am trying to update quote in cart page.All working fine except price.The price is not getting updated quote and quoteitem database table and in summary also.Can anyone help me.

<?php
namespace Vender\Module\Observer;
use Magento\Framework\Event\ObserverInterface;
class PredispatchCheckoutCart implements ObserverInterface{

    public function __construct(
        \Magento\Framework\ObjectManagerInterface $_objectManager,
        \Magento\Framework\App\Request\Http $_request,
        \Magento\Framework\Message\ManagerInterface $_messangeManager,
        \Magento\Checkout\Helper\Cart $_cartHelper
    ) {
        $this->_objectManager = $_objectManager;
        $this->_request = $_request;
        $this->_messangeManager = $_messangeManager;
        $this->_cartHelper = $_cartHelper;
    }

    public function execute(\Magento\Framework\Event\Observer $observer){

            $quoteId = intval($this->_request->getParam('quoteId'));  
            $cartsess = $this->_objectManager->get('Magento\Checkout\Model\Session');
            $cartsess->setQuoteId($quoteId);
            $cartsess->setLoadInactive(true);
            $quote = $cartsess->getQuote();
            $quote->setIsActive(true);
            $quote->save();
            $quote->setTotalsCollectedFlag(false)->collectTotals();
            $this->_messangeManager->addSuccess('Product is successfully added in to cart.');   
            $redirectUrl = $this->_cartHelper->getCartUrl();
            $observer->getControllerAction()->getResponse()->setRedirect($redirectUrl);

        }
    }
}

Answer 1

For Recalculate total below code works for me.

$quote->setTriggerRecollect(1); //Magic line.
$quote->collectTotals();
$quote->save();

Answer 2

May you forgot to save the collect total. We can try

$quote->setTotalsCollectedFlag(false)->collectTotals()->save()

or

$cartsess->getQuote()->collectTotals()->save()