如果我很了解您想要在元框中显示小部件的添加和删除界面。

一种简单的、有点脏的方法是使用iframe：

function metaboxed_widgets_admin() {
  if ( ! current_user_can( \'edit_theme_options\' ) ) return;
  add_meta_box(\'metaboxed_widgets\', __(\'Widgets\'), \'metaboxed_widgets_admin_cb\', \'page\');
}
add_action( \'add_meta_boxes\', \'metaboxed_widgets_admin\' );

function metaboxed_widgets_admin_cb() {
  if ( ! current_user_can( \'edit_theme_options\' ) ) return;
  $format = \'<div style="margin:0px;padding:0px;">\';
  $format .= \'<iframe src="%s" frameborder="0" %s></iframe></div>\';
  // add a query arg to recognize when inside iframe, used to hide menu and admin bar
  $url = add_query_arg(
    array( \'iframe\'=> wp_create_nonce(\'widgets\') ), admin_url( \'widgets.php\' )
  );
  printf( $format, $url, \'style="height:1200px;width:100%;" height="100%" width="100%"\' );
}

function metaboxed_widgets_hide_stuff() {
  if ( ! is_admin() || get_current_screen()->id !== \'widgets\' ) return;  
  $iframe = filter_input( INPUT_GET, \'iframe\', FILTER_SANITIZE_STRING );
  if ( wp_verify_nonce( $iframe, \'widgets\' ) ) {
    echo \'<style>\'
    . \'#wpadminbar, #adminmenuback, #adminmenuwrap, #wpfooter, \'
    . \'#screen-meta-links, .wrap > h2 { display:none!important; }\'
    . \'#wpcontent { margin-left:25px!important; }\'
    . \'.wrap{ margin-top:0!important; }</style>\';
  }
}
add_action( \'admin_head-widgets.php\', \'metaboxed_widgets_hide_stuff\' );