【Unity UGUI】ScreenPointToLocalPointInRectangle和Rect.Contains判断屏幕坐标是否在指定UI区域内

RectTransformUtility.ScreenPointToLocalPointInRectangle：

将屏幕坐标转化为相对RectTransform的本地坐标

RectTransform.rect.Contains：

判断坐标点是否在Rect矩形内，RectTransform.rect是相对于RectTransform的本地坐标

    RectTransform rectTrans = transform as RectTransform;
    Vector2 screenPoint = Input.mousePosition;
    Camera uiCamera = Camera.main;
    Vector2 localPoint;
    
    //将屏幕坐标转化为相对rectTrans的本地坐标
    if(RectTransformUtility.ScreenPointToLocalPointInRectangle(rectTrans,screenPoint,uiCamera,out localPoint))
    {
        //判断坐标点是否在rectTrans.rect矩形内
        if(rectTrans.rect.Contains(localPoint))
        {
            //rectTrans.rect是rectTrans的本地坐标，不能rectTrans.rect.Contains(screenPoint)直接判断，必须先转为本地坐标localPoint
            Debug.Log("屏幕坐标在rectTrans范围内");
        }
    }