Actorbox.php 应该在 formwidgets 路径中.如果正确创建目录结构将像

The Actorbox.php should be in the formwidgets path. If properly created the dir structure would be like

|-- formwidgets
|  
|-- ActorBox.php
|   `-- actorbox
|       |-- assets
|       |   |-- css
|       |   |   |-- actorbox.css
|       |   |   `-- select2.min.css
|       |   `-- js
|       |       |-- actorbox.js
|       |       `-- select2.min.js
|       `-- partials
|           `-- _actorbox.htm