Mrthdrb

I have installed magento 2.0.7 and overide the template minicart.phtml to my custom theme. I want to show total price and total items in the header minicart like the below image

I believe you will need to use AJAX along with the API unless there is already a function for this in the Magento/Checkout/Model... Find the minicart knockout js template for an example already in your code.

http://devdocs.magento.com/guides/v2.0/javascript-dev-guide/javascript/js_overview.html

http://devdocs.magento.com/guides/v2.0/extension-dev-guide/bk-extension-dev-guide.html

Please make a copy of minicart.phtml file in your theme (appdesignfrontendyourpackageyourthemeMagento_Checkouttemplatescartminicart.phtml) and add the below code in it

<?php
/**
 * Copyright © 2016 Magento. All rights reserved.
 * See COPYING.txt for license details.
 */

// @codingStandardsIgnoreFile

/** @var $block MagentoCheckoutBlockCartSidebar */
?>
<?php $helper = $this->helper('MagentoCheckoutHelperCart');?>
<div data-block="minicart" class="minicart-wrapper">
 <a class="action showcart" href="<?php /* @escapeNotVerified */ echo $block->getShoppingCartUrl(); ?>"
 data-bind="scope: 'minicart_content'">
 <span class="text"><?php /* @escapeNotVerified */ echo __('Shopping Cart'); ?></span>
 <span class="counter qty empty"
 data-bind="css: empty: cart().summary_count < 0 , blockLoader: isLoading">
 <span class="ex-top-cart-subtotal">
 <!-- ko if: cart().summary_count -->
 <!-- ko if: cart().possible_onepage_checkout -->
 <!-- ko foreach: getRegion('subtotalContainer') -->
 <!-- ko template: getTemplate() --><!-- /ko -->&nbsp;-&nbsp;
 <!-- /ko -->
 <!-- /ko -->
 <!-- /ko --></span>

 <span class="counter-label">
 <!-- ko ifnot: cart().summary_count -->
 &pound; <!-- ko i18n: ' 0.00 - 0 item ' --><!-- /ko -->
 <!-- /ko -->
 <!-- ko if: cart().summary_count -->
 <!-- ko text: cart().summary_count --><!-- /ko -->
 <!-- ko if: cart().summary_count == 1 -->
 <!-- ko i18n: 'item' --><!-- /ko -->
 <!-- /ko -->
 <!-- ko if: cart().summary_count > 1 -->
 <!-- ko i18n: 'items' --><!-- /ko -->
 <!-- /ko -->
 <!-- /ko -->

 <?php //echo "&pound; ".number_format($helper->getQuote()->getSubtotal(), 2, '.', '');?>
 </span>

 </span>
 </a>
 <?php if ($block->getIsNeedToDisplaySideBar()): ?>
 <div class="block block-minicart empty"
 data-role="dropdownDialog"
 data-mage-init='"dropdownDialog":
 "appendTo":"[data-block=minicart]",
 "triggerTarget":".showcart",
 "timeout": "2000",
 "closeOnMouseLeave": false,
 "closeOnEscape": true,
 "triggerClass":"active",
 "parentClass":"active",
 "buttons":[]'>
 <div id="minicart-content-wrapper" data-bind="scope: 'minicart_content'">
 <!-- ko template: getTemplate() --><!-- /ko -->
 </div>
 </div>
 <?php endif ?>
 <script>
 window.checkout = <?php /* @escapeNotVerified */ echo Zend_Json::encode($block->getConfig()); ?>;
 </script>
 <script type="text/x-magento-init">
 
 "[data-block='minicart']": 
 "Magento_Ui/js/core/app": <?php /* @escapeNotVerified */ echo $block->getJsLayout();?>
 ,
 "*": 
 "Magento_Ui/js/block-loader": "<?php /* @escapeNotVerified */ echo $block->getViewFileUrl('images/loader-1.gif'); ?>"
 
 
 </script>
</div>

Go to this directory appdesignfrontendyourpackageyourthemeMagento_Checkouttemplatescartminicart.phtml

and overwrite with below code in minicart.phtml file.

<a class="action showcart" href="<?php /* @escapeNotVerified */ echo $block->getShoppingCartUrl(); ?>"
 data-bind="scope: 'minicart_content'">
 <span class="text"><?php /* @escapeNotVerified */ echo __('My Cart'); ?></span> 
 <span class="counter qty empty" data-bind="css: empty: cart().summary_count == 0 , css: empty: !cart().summary_count , blockLoader: isLoading">
 <span class="counter-number"> 

 <!-- ko if: !cart().summary_count -->
 <!-- ko i18n: '0 item' --><!-- /ko -->
 <!-- /ko --> 
 <!-- ko if: cart().summary_count >= 1 -->
 <!-- ko text: cart().summary_count --><!-- /ko --> 
 <!-- ko i18n: ' items' --><!-- /ko -->
 <!-- /ko --> 
 </span> 
 <span class="price-wrapper" data-bind="html: cart().subtotal_excl_tax"> </span> 
 <span class="price-custom-minicart">
 <!-- ko if: !cart().subtotal_excl_tax -->
 <!-- ko i18n: '€ 0.00' --><!-- /ko -->
 <!-- /ko -->
 </span>
 <span class="counter-label">
 <!-- ko if: cart().summary_count -->
 <!-- ko text: cart().summary_count --><!-- /ko -->
 <!-- ko i18n: 'items' --><!-- /ko -->
 <!-- /ko -->
 </span>
 </span>
</a>

Working code for me. Magento 2.2.4

<a class="action showcart" href="<?php /* @escapeNotVerified */ echo $block->getShoppingCartUrl(); ?>"
 data-bind="scope: 'minicart_content'">
 <span class="counter qty empty"
 data-bind="css: empty: !!getCartParam('summary_count') == false , blockLoader: isLoading">
 <span class="counter-number">
 <!-- ko ifnot: getCartParam('summary_count') -->
 <!-- ko text: '0' --><!-- /ko -->
 <!-- /ko -->
 <!-- ko if: getCartParam('summary_count') -->
 <!-- ko text: getCartParam('summary_count') --><!-- /ko -->
 <!-- /ko -->
 </span>
 <span class="counter-label">
 <!-- ko if: getCartParam('summary_count') -->
 <!-- ko text: getCartParam('summary_count') --><!-- /ko -->
 <!-- ko i18n: 'items' --><!-- /ko -->
 <!-- /ko -->
 </span>
 </span>

 <span class="text"><?php /* @escapeNotVerified */ echo __('My Cart'); ?></span>

 <span data-bind="html: getCartParam('subtotal')"></span>
 <!-- /ko -->
 <!-- ko if: getCartParam('summary_count') != 1 -->
 <!-- ko text: getCartParam('summary_count') --><!-- /ko -->
 <!-- ko i18n: 'items' --><!-- /ko -->
 <span data-bind="html: getCartParam('subtotal')"></span>
 <!-- /ko -->
 </span>

 </a>