我们可以在post第一次发布时将值存储到POSTETA中。

function save_ispublished( $post_id ) {

    if (defined(\'DOING_AUTOSAVE\') && DOING_AUTOSAVE)
        return;

    $published_once = get_post_meta( $post_id, \'is_published\', true );

    // Check if \'is_published\' meta value is empty.
    if ( ! empty( $published_once ) ) {

        $published_once = \'yes\';
    }

    // store is_published value when first time published.
    update_post_meta( $post_id, \'is_published\', $published_once );
}
add_action( \'save_post\', \'save_ispublished\' );

$is_published = get_post_meta( $post_id, \'is_published\', true );

if( $is_published == \'yes\' ) {

    /*
    * Actions if post is already published atleast once.
    */
}