使用the_content 筛选以将字段添加到的输出中the_content() 功能：

function wpd_content_filter( $content ) {
    if ( \'your_custom_type\' == get_post_type() ){
        if( $meta = get_post_meta( get_the_ID(), \'foo_meta\', true ) ) {
           $content = $content . $meta;
        }
    }
    return $content;
}
add_filter( \'the_content\', \'wpd_content_filter\' );