这是我的php，用于创建带有缩略图的帖子。我想知道如何将上传的图像添加到帖子内容中。尝试了一些事情，但都没有成功。

 if(isset($_POST[\'new_post\']) == \'1\') {

        $post_title = $_POST[\'post_title\'];
        $post_category = $_POST[\'cat\'];
        $filename = $_POST[\'attach\'];

       $new_post = array(
          \'ID\' => \'\',
          \'post_author\' => $current_user->ID, 
          \'post_category\' => array($post_category),
          \'post_title\' => $post_title,
          \'post_status\' => \'draft\'
        );

        $post_id = wp_insert_post($new_post);
        $post = get_post($post_id);
        $new_post = $post->ID;

     if (!function_exists(\'wp_generate_attachment_metadata\')){
            require_once(ABSPATH . "wp-admin" . \'/includes/image.php\');
            require_once(ABSPATH . "wp-admin" . \'/includes/file.php\');
            require_once(ABSPATH . "wp-admin" . \'/includes/media.php\');
            }

             if ($_FILES) {
            foreach ($_FILES as $file => $array) {
                if ($_FILES[$file][\'error\'] !== UPLOAD_ERR_OK) {
                    return "upload error : " . $_FILES[$file][\'error\'];
                }
                $attach_id = media_handle_upload( $file, $new_post );
            }   
            }

            if ($attach_id > 0){

            //and if you want to set that image as Post  then use:
            update_post_meta($new_post,\'_thumbnail_id\',$attach_id);
            }

}