WordPress 中的自定义主题不显示任何内容

如何解决WordPress 中的自定义主题不显示任何内容

style.css

/*
Theme Name: My First Theme
Theme URI: http://localhost/wordpress/
Author: Itsmee
Author URI: https://abcd.com
Description: Basic wordpress theme for Sitepoint theme building tutorial
Text Domain: bsimple
Version: 1.0.0
License: GNU General Public License v2 or later
*/

index.PHP

<?PHP
/**
 * The main template file
 *
 * This is the most generic template file in a wordpress theme
 * and one of the two required files for a theme (the other being style.css).
 * It is used to display a page when nothing more specific matches a query.
 * E.g.,it puts together the home page when no home.PHP file exists.
 *
 * @package My_First_Theme
 */

get_header();
?>

//content HTML here

<?PHP get_footer(); ?>

header.PHP

 <?PHP wp_head(); ?>
    <head>
      <Meta charset="utf-8">
      <Meta content="width=device-width,initial-scale=1.0" name="viewport">
    
      <title>Bootstrap Template - Index</title>
      <Meta content="" name="description">
      <Meta content="" name="keywords">
    
      <!-- Favicons -->
      <link href="assets/img/favicon.png" rel="icon">
      <link href="assets/img/apple-touch-icon.png" rel="apple-touch-icon">
    
      <!-- Google Fonts -->
      <link href="https://fonts.googleapis.com/css?family=Open+Sans:300,400,400i,600,700|Raleway:300,500,500i,700,800,900" rel="stylesheet">
    
      <!-- vendor CSS Files -->
      <link href="assets/vendor/bootstrap/css/bootstrap.min.css" rel="stylesheet">
      <link href="assets/vendor/icofont/icofont.min.css" rel="stylesheet">
      <link href="assets/vendor/animate.css/animate.min.css" rel="stylesheet">
      <link href="assets/vendor/font-awesome/css/font-awesome.min.css" rel="stylesheet">
      <link href="assets/vendor/nivo-slider/css/nivo-slider.css" rel="stylesheet">
      <link href="assets/vendor/owl.carousel/assets/owl.carousel.min.css" rel="stylesheet">
      <link href="assets/vendor/venoBox/venoBox.css" rel="stylesheet">
    
      <!-- Template Main CSS File -->
      <link href="assets/css/style.css" rel="stylesheet">
    
      
    </head>

页脚.PHP

<?PHP wp_footer(); ?>
//Footer scripts and other contents

成功创建主题并在后台激活但在前端看不到任何东西，好像主题文件没有渲染。

请帮忙！谢谢。