Unity UI實(shí)現(xiàn)拖拽旋轉(zhuǎn)

更新時(shí)間：2021年06月06日 17:11:01 作者：ᴸᴵᴬᴺᴳᴬᴬ

這篇文章主要為大家詳細(xì)介紹了Unity UI實(shí)現(xiàn)拖拽旋轉(zhuǎn)，文中示例代碼介紹的非常詳細(xì)，具有一定的參考價(jià)值，感興趣的小伙伴們可以參考一下

本文實(shí)例為大家分享了Unity UI實(shí)現(xiàn)拖拽旋轉(zhuǎn)的具體代碼，供大家參考，具體內(nèi)容如下

跟隨鼠標(biāo)旋轉(zhuǎn)

第一種效果是跟隨鼠標(biāo)旋轉(zhuǎn)，原理是計(jì)算下鼠標(biāo)位置與拖拽物體的相對(duì)位移

旋轉(zhuǎn)方向即可

注意轉(zhuǎn)換對(duì)應(yīng)空間坐標(biāo)

新建腳本mono類繼承 IBeginDragHandler, IDragHandler, IEndDragHandler 接口

[SerializeField] private Canvas m_Canvas;
    
    private Vector3? CalculateWorldToScreenPos(Vector3 worldPos)
    {
        if (m_Canvas.renderMode == RenderMode.ScreenSpaceCamera)
        {
            return m_Canvas.worldCamera.WorldToScreenPoint(worldPos);
        }
        else if (m_Canvas.renderMode == RenderMode.ScreenSpaceOverlay)
        {
            Vector3 screenPos = m_Canvas.transform.InverseTransformPoint(worldPos);
            var rectTrans = m_Canvas.transform as RectTransform;
            screenPos.x += rectTrans.rect.width * 0.5f * rectTrans.localScale.x;
            screenPos.y += rectTrans.rect.height * 0.5f * rectTrans.localScale.y;
            return screenPos;
        }

        return null;
    }
    
    public void OnDrag(PointerEventData eventData)
    {
        if (eventData.button != PointerEventData.InputButton.Left) return;
        
        //計(jì)算當(dāng)前物體距離畫布左下角位置
        Vector3? curScreenPos = CalculateWorldToScreenPos(transform.position);
        if (curScreenPos == null) return;
        //鼠標(biāo)位置偏移量
        Vector2 offset = eventData.position - (Vector2)curScreenPos.Value;
        if (offset != Vector2.zero)
        {
            transform.rotation = Quaternion.FromToRotation(Vector3.up, offset);
        }
    }

設(shè)置下箭頭錨點(diǎn)

效果如下：

手指拖拽旋轉(zhuǎn)

第二種是根據(jù)旋轉(zhuǎn)速度來旋轉(zhuǎn)UI 可以實(shí)現(xiàn)一些齒輪交互滾動(dòng)和車把方向盤交互滾動(dòng)

//旋轉(zhuǎn)速度
[SerializeField] private float m_RotateSpeed;
    
    public void OnDrag(PointerEventData eventData)
    {
        if (eventData.button != PointerEventData.InputButton.Left) return;

        //手指滑動(dòng)偏移量
        Vector2 mouseXY = eventData.delta;
        mouseXY *= m_RotateSpeed;

        //計(jì)算當(dāng)前物體距離畫布左下角位置
        Vector3? curScreenPos = CalculateWorldToScreenPos(transform.position);
        if (curScreenPos == null) return;
        //手指位置偏移量
        Vector2 offset = eventData.position - (Vector2)curScreenPos.Value;

        float value;
        if (Mathf.Abs(mouseXY.x) > Mathf.Abs(mouseXY.y)) // 判斷水平滑動(dòng)還是垂直滑動(dòng)
        {
            //手指往水平滑動(dòng)   下面旋轉(zhuǎn)跟隨偏移參數(shù)  上面與偏移參數(shù)相反
            value = mouseXY.x * Mathf.Sign(-offset.y);
        }
        else
        {
            //手指垂直滑動(dòng)    右邊跟隨偏移參數(shù)    左邊與偏移參數(shù)相反
            value = mouseXY.y * Mathf.Sign(offset.x);
        }

        transform.Rotate(Vector3.forward, value, Space.Self);

    }

效果如下：