Unity手游输入笔记

虚拟摇杆

1. 虚拟摇杆生效的范围通常是左半屏，放一个左半屏的透明image，挂载脚本；
2. 有摇杆座、摇杆头2个图标；
3. 脚本继承IPointerDown、IPointerUp、IPointerDrag；
4. 按下时把摇杆座放到按下位置，使用

   public void OnPointerDown(PointEventData eventData){Vector2 pos;RectTransformUtility.ScreenPointToLocalPointInRectangle(transform as RectTransform,eventData.position,eventData.pressEventCamera,out pos);joystick.transform.localPosition=pos;
   }

5. 拖动时把摇杆头移到触摸点，但不超过摇杆座范围

   float joystickRadius;
   public void OnDrag(PointEventData eventData){Vector2 pos;RectTransformUtility.ScreenPointToLocalPointInRectangle(joystick.transform as RectTransform,eventData.position,eventData.pressEventCamera,out pos);if(pos.magnitude>joystickRadius){pos=pos.normalized*joystickRadius;}joystickHead.transform.localPosition=pos;
   }

6. 触摸离开时把摇杆归位或消失

   public void OnPointerUp(PointEventData eventData){joystick.transform.localPosition=initPos;joystickHead.localPosition=Vector3.zero;
   }