是否有一个钩子实际上只在帖子更新时触发，我在哪里可以在更新之前和之后获得$post\\u？

你可能在找post_updated 钩

使用情况

add_action( \'post_updated\', \'wpse_264720_post_updated\', 10, 3 );
function wpse_264720_post_updated( $post_ID, $post_after, $post_before ) {

  //* Bail if this is an autosave
  if( defined( \'DOING_AUTOSAVE\' ) && DOING_AUTOSAVE ) {
    return;
  }

  //* Bail if this is a post revision
  if( wp_is_post_revision( $post_ID ) ) {
    return;
  }

  //* Bail if not the correct post types
  if( ! in_array( $post_after->post_type, [ \'post-type-1\', \'post-type-2\' ] ) ) {
    return;
  }

  //* If you add/update/delete posts, remove action to avoid infinite loop
  remove_action( \'post_updated\', \'wpse_264720_post_updated\', 10 );

  //* Do something useful after the post was updated

  //* If the post was updated, remove save_post action
  remove_action( \'save_post\', \'wpse_264720_save_post\', 10, 3 );
}
//* Hypothetical function hooked to save_post
add_action( \'save_post\', \'wpse_264720_save_post\', 10, 3 );
function wpse_264720_save_post( $post_id, $post, $update ) {
  //* Bail if post was an update
  if( $update ) {
    return;
  }
  //* Do something useful on save_post
}