Unity实现2D物体拖拽效果

方法1：简单粗暴，给物体上挂上一个拖拽脚本，实现OnMouseDrag()方法，上图
方法2：给物体上挂上一个拖拽脚本，实现接口IDragHandler，上图、

方法3：直接上代码

    void Update()
    {
        if (Input.GetMouseButtonDown(0))
        {
            isMouseDown = true;
        }
        if (Input.GetMouseButtonUp(0))
        {
            isMouseDown = false;
            lastMousePosition = Vector3.zero;
            isClickObj = false;
        }
        if (isMouseDown)
        {
            RaycastHit2D raycastHit2D =
                Physics2D.Raycast(Camera.main.ScreenToWorldPoint(Input.mousePosition), Vector2.zero, 100);
            Debug.Log(raycastHit2D.collider);
            if (raycastHit2D.collider != null)
            {
                if (raycastHit2D.collider.transform == transform)
                {
                    isClickObj = true;
                }
            }
            if (isClickObj)
            {
                Move();
            }
        }
    }
    private void Move()
    {
        if (lastMousePosition != Vector3.zero)
        {
            Vector3 offset = Camera.main.ScreenToWorldPoint(Input.mousePosition) - lastMousePosition;
            this.transform.position += offset;
        }
        lastMousePosition = Camera.main.ScreenToWorldPoint(Input.mousePosition);
    }

方法4：使用FingerGestures插件来实现拖拽
注意，场景中要拖入FingerGestures手势检测预制体，物体上挂DragRecognizer和ScreenRaycaster脚本

方法5：有待添加