我刚刚编写了以下代码，您可以试用：

add_filter( \'the_content\', \'restrict_access\' );
function restrict_access( $content ) { 

    $user_info = wp_get_current_user(); // Get logged in user info
    $registered = $user_info->user_registered;

    if( !is_user_logged_in() ) {

        $content = __( "You are not logged in.", \'your_textdomain\' );

    } else if (new DateTime( get_the_date() ) < new DateTime( $registered )) {

        $content = __( "You are not allowed to view this content. Your user was registered ( ".date( "d-m-Y", strtotime( $registered ) )." ) after content was created ( ".get_the_date( "d-m-Y" )." ) , you are only allowed to view new content.", \'your_textdomain\' );

    }

    return $content;
}