load_theme_textdomain( string $domain, string $path = false )

加载主题的翻译字符串。
Load the theme’s translated strings.

目录锚点：#说明#参数#返回#源码#笔记

说明（Description）

如果当前区域设置作为.mo文件存在于主题的根目录中，则$domain会将其包含在翻译的字符串中。

.mo文件的命名必须完全基于区域设置。

参数（Parameters）

返回（Return）

（bool）成功加载textdomain时为True，否则为false。

源码（Source）

/**
 * Load the theme's translated strings.
 *
 * If the current locale exists as a .mo file in the theme's root directory, it
 * will be included in the translated strings by the $domain.
 *
 * The .mo files must be named based on the locale exactly.
 *
 * @since 1.5.0
 *
 * @param string $domain Text domain. Unique identifier for retrieving translated strings.
 * @param string $path   Optional. Path to the directory containing the .mo file.
 *                       Default false.
 * @return bool True when textdomain is successfully loaded, false otherwise.
 */
function load_theme_textdomain( $domain, $path = false ) {
	$locale = get_locale();
	/**
	 * Filter a theme's locale.
	 *
	 * @since 3.0.0
	 *
	 * @param string $locale The theme's current locale.
	 * @param string $domain Text domain. Unique identifier for retrieving translated strings.
	 */
	$locale = apply_filters( 'theme_locale', $locale, $domain );

	if ( ! $path )
		$path = get_template_directory();

	// Load the textdomain according to the theme
	$mofile = untrailingslashit( $path ) . "/{$locale}.mo";
	if ( $loaded = load_textdomain( $domain, $mofile ) )
		return $loaded;

	// Otherwise, load from the languages directory
	$mofile = WP_LANG_DIR . "/themes/{$domain}-{$locale}.mo";
	return load_textdomain( $domain, $mofile );
}

笔记（Notes）

第一个例子
第二个例子