如何通过编程在自定义控件中引发现有事件?

I have made a custom class by inheriting a DateTimePicker and made some methods that allow it to be blank/null.

If the control is blank and a user clicks on it, it populates with the current date. It also raises the ValueChanged 事件。

如果控件填充并且用户按下删除,则它清除并将其值设置为NULL,但 更改值 事件 不会触发。

在控件中 OnKeyDown method, I would like to include some code that raises the 更改值 event, but there doesn't seem to be a way to do that.

Do I need to override the base class event? Is there an applicable example?