工具提示并非用于输入文本:它们仅用于显示信息.您必须使用MouseHover事件和(可能是)自定义控件来复制功能.

Tooltips are not meant for text entry: they are only for display information. You will have to duplicate the functionality yourself, using the MouseHover Event and (probably) a custom control.

I'll draw a circle through the System.Draqwing
 Inside the circle I can display photos
 How can the circle filled with TextBox?