Question

switch_to_blog( int $new_blog,  bool $deprecated = null )

Switch the current blog.

---

description

This function is useful if you need to pull posts, or other information, from other blogs. You can switch back afterwards using restore_current_blog().

Things that aren’t switched:

• autoloaded options. See
• plugins. See

---

参数

$new_blog

(int) (Required) The id of the blog you want to switch to. Default: current blog

$deprecated

(bool) (Optional) Deprecated argument

Default value: null

---

返回值

(true) Always returns True.

---

源代码

File: wp-includes/ms-blogs.php

function switch_to_blog( $new_blog, $deprecated = null ) {
	global $wpdb, $wp_roles;

	$blog_id = get_current_blog_id();
	if ( empty( $new_blog ) ) {
		$new_blog = $blog_id;
	}

	$GLOBALS['_wp_switched_stack'][] = $blog_id;

	/*
	 * If we're switching to the same blog id that we're on,
	 * set the right vars, do the associated actions, but skip
	 * the extra unnecessary work
	 */
	if ( $new_blog == $blog_id ) {
		/**
		 * Fires when the blog is switched.
		 *
		 * @since MU
		 *
		 * @param int $new_blog New blog ID.
		 * @param int $new_blog Blog ID.
		 */
		do_action( 'switch_blog', $new_blog, $new_blog );
		$GLOBALS['switched'] = true;
		return true;
	}

	$wpdb->set_blog_id( $new_blog );
	$GLOBALS['table_prefix'] = $wpdb->get_blog_prefix();
	$prev_blog_id = $blog_id;
	$GLOBALS['blog_id'] = $new_blog;

	if ( function_exists( 'wp_cache_switch_to_blog' ) ) {
		wp_cache_switch_to_blog( $new_blog );
	} else {
		global $wp_object_cache;

		if ( is_object( $wp_object_cache ) && isset( $wp_object_cache->global_groups ) ) {
			$global_groups = $wp_object_cache->global_groups;
		} else {
			$global_groups = false;
		}
		wp_cache_init();

		if ( function_exists( 'wp_cache_add_global_groups' ) ) {
			if ( is_array( $global_groups ) ) {
				wp_cache_add_global_groups( $global_groups );
			} else {
				wp_cache_add_global_groups( array( 'users', 'userlogins', 'usermeta', 'user_meta', 'useremail', 'userslugs', 'site-transient', 'site-options', 'blog-lookup', 'blog-details', 'rss', 'global-posts', 'blog-id-cache', 'networks', 'sites', 'site-details' ) );
			}
			wp_cache_add_non_persistent_groups( array( 'counts', 'plugins' ) );
		}
	}

	if ( did_action( 'init' ) ) {
		$wp_roles = new WP_Roles();
		$current_user = wp_get_current_user();
		$current_user->for_blog( $new_blog );
	}

	/** This filter is documented in wp-includes/ms-blogs.php */
	do_action( 'switch_blog', $new_blog, $prev_blog_id );
	$GLOBALS['switched'] = true;

	return true;
}

---

更新日志

Version	description
MU	Introduced.

---

相关函数

Uses

• wp-includes/class-wp-roles.php: WP_Roles::__construct()
• wp-includes/cache.php: wp_cache_switch_to_blog()
• wp-includes/cache.php: wp_cache_init()
• wp-includes/cache.php: wp_cache_add_global_groups()
• wp-includes/cache.php: wp_cache_add_non_persistent_groups()
• wp-includes/pluggable.php: wp_get_current_user()
• wp-includes/load.php: get_current_blog_id()
• wp-includes/plugin.php: do_action()
• wp-includes/plugin.php: did_action()
• wp-includes/ms-blogs.php: switch_blog
• wp-includes/wp-db.php: wpdb::set_blog_id()
• wp-includes/wp-db.php: wpdb::get_blog_prefix()
Show 7 more uses Hide more uses

---

Used By

• wp-includes/class-wp-site.php: WP_Site::get_details()
• wp-includes/general-template.php: has_custom_logo()
• wp-includes/general-template.php: get_custom_logo()
• wp-includes/general-template.php: get_site_icon_url()
• wp-admin/includes/class-wp-ms-sites-list-table.php: WP_MS_Sites_List_Table::column_blogname()
• wp-signup.php: confirm_another_blog_signup()
• wp-admin/includes/ms.php: wpmu_delete_user()
• wp-admin/includes/ms.php: upload_space_setting()
• wp-admin/includes/ms.php: wpmu_delete_blog()
• wp-admin/includes/class-wp-users-list-table.php: WP_Users_List_Table::get_views()
• wp-admin/includes/class-wp-importer.php: WP_Importer::set_blog()
• wp-includes/capabilities.php: current_user_can_for_blog()
• wp-includes/class-wp-theme.php: WP_Theme::get_allowed_on_site()
• wp-includes/link-template.php: get_home_url()
• wp-includes/link-template.php: get_site_url()
• wp-includes/admin-bar.php: wp_admin_bar_my_sites_menu()
• wp-includes/ms-functions.php: wpmu_create_blog()
• wp-includes/ms-functions.php: newblog_notify_siteadmin()
• wp-includes/ms-functions.php: get_blog_post()
• wp-includes/ms-functions.php: add_user_to_blog()
• wp-includes/ms-functions.php: remove_user_from_blog()
• wp-includes/ms-deprecated.php: create_empty_blog()
• wp-includes/ms-functions.php: get_blog_permalink()
• wp-includes/ms-blogs.php: update_blog_details()
• wp-includes/ms-blogs.php: get_blog_option()
• wp-includes/ms-blogs.php: add_blog_option()
• wp-includes/ms-blogs.php: delete_blog_option()
• wp-includes/ms-blogs.php: update_blog_option()
• wp-includes/ms-blogs.php: get_blog_details()
• wp-includes/class-wp-xmlrpc-server.php: wp_xmlrpc_server::wp_getUsersBlogs()
Show 25 more used by Hide more used by

---

User Contributed Notes

1. Skip to note content You must log in to vote on the helpfulness of this noteVote results for this note: 0You must log in to vote on the helpfulness of this note Contributed by Codex

   One switch

   
   switch_to_blog( $blog_id );
   // Do something
   restore_current_blog();
   

Multiple switches

foreach( $blog_ids as $blog_id ){
    switch_to_blog( $blog_id );
    //Do stuff
    restore_current_blog();
}

If you do not call restore_current_blog() after every switch_to_blog(), WordPress can get into a state that can potentially build the wrong urls for the site. See restore_current_blog() vs switch_to_blog().

description

Restores previous blog after a switch_to_blog call.

Contrary to the function’s name, this does NOT restore the original blog but the previous blog. Calling `switch_to_blog()` twice in a row and then calling this function will result in being on the blog set by the first `switch_to_blog()` call.