We're creating a plugin where, for example, it shows a metabox on all post types. To kick things off, I'm using the Starter Kit.

<?php

namespace PLUGIN_NAME;

class Foo
{
  public function __construct() {
    add_action( 'admin_init', [ $this, 'wpd_add_meta_box' ] );
  }

function wpd_add_meta_box() {
        $screens = get_post_types();
        foreach ( $screens as $screen ) {
            add_meta_box(
                'global-notice',
                __( 'Global Box 

                                发布者：admin，转转请注明出处：http://www.yc00.com/questions/1745229225a4617603.html