这可以通过两个过滤器完成，attachment_fields_to_edit 和attachment_fields_to_save, 这完全符合他们的名字。假设您想添加source 领域首先，生成字段并用其当前值（如果存在）填充它：

function wpse133608_add_attachment_location_field( $form_fields, $post ) {
    $field_value = get_post_meta( $post->ID, \'source\', true );
    $form_fields[\'source\'] = array(
        \'value\' => $field_value ? $field_value : \'\',
        \'label\' => __( \'Source\' ),
        \'helps\' => __( \'Set a source for this attachment\' )
    );
    return $form_fields;
}
add_filter( \'attachment_fields_to_edit\', \'wpse133608_add_attachment_location_field\', 10, 2 );

function wpse133608add_image_attachment_fields_to_save( $post, $attachment ) {
    if ( isset( $attachment[\'source\'] ) )
        update_post_meta( $post[\'ID\'], \'_source\', esc_attr($attachment[\'source\']) );

    return $post;
}
add_filter("attachment_fields_to_save", "wpse133608_add_image_attachment_fields_to_save", null , 2);