描述：

获取页面链接

用法：

<?php get_page_link($id, $leavename, $sample); ?>

参数：

$id

(mixed) (可选) 页面ID

默认值: false

$leavename

(bool) (可选) 是否保留页面名称

默认值: false

$sample

(bool) (可选) Is it a sample permalink?

默认值: false

源文件：

<?php
...
function is_attachment( $attachment = '' ) {
    global $wp_query;

    if ( ! isset( $wp_query ) ) {
        _doing_it_wrong( __FUNCTION__, __( 'Conditional query tags do not work before the query is run. Before then, they always return false.' ), '3.1.0' );
        return false;
    }

    return $wp_query->is_attachment( $attachment );
}

...
?>