亲测无效
<?php
//Checking User logedin or not
$objectManager = \Magento\Framework\App\ObjectManager::getInstance();
$context = $objectManager->get('Magento\Framework\App\Http\Context');
$isLoggedIn = $context->getValue(\Magento\Customer\Model\Context::CONTEXT_AUTH);
$customerSession = $objectManager->create("Magento\Customer\Model\Session");
if($customerSession->isLoggedIn()){
//getting customer ID
$id = $customerSession->getCustomerID();}
//Getting wishlist products Collections Related to Customers
$wishlist = $objectManager->get('\Magento\Wishlist\Model\Wishlist');
$wishlist_collection = $wishlist->loadByCustomerId($id , true)->getItemCollection();
$_in_wishlist = "false";
foreach ($wishlist_collection as $wishlist_product):
if($_product->getId() == $wishlist_product->getProduct()->getId()){
$_in_wishlist = "true";
break;
}
endforeach;
if($_in_wishlist == "true"): ?>
<div class="addtowishlist added" style="font-family: Raleway"><span>Already Added to Wishlist:</span><div data-role="add-to-links" class="actions-secondary"<?= strpos($pos, $viewMode . '-secondary') ? $position : '' ?>>
<?php if ($addToBlock = $block->getChildBlock('addto')): ?>
<?= $addToBlock->setProduct($_product)->getChildHtml() ?>
<?php endif; ?>
</div>
</div>
<?php else: ?>
<div class="addtowishlist" style="font-family: Raleway"><span>Add to Wishlist:</span><div data-role="add-to-links" class="actions-secondary"<?= strpos($pos, $viewMode . '-secondary') ? $position : '' ?>>
<?php if ($addToBlock = $block->getChildBlock('addto')): ?>
<?= $addToBlock->setProduct($_product)->getChildHtml() ?>
<?php endif; ?>
</div>
</div>
<?php endif; ?>