//方式一，使用API获取

        var rtrans = gameObject.GetComponent<RectTransform>();

        Vector3[] worldcorners = new Vector3[];

        rtrans.GetWorldCorners(worldcorners);

        //方式二，手动计算

        var cam = GameObject.Find("Camera").GetComponent<Camera>();

        var cam_h =  * cam.orthographicSize;

        var cam_w = cam_h * Screen.width / Screen.height;

        var canvasObj = GameObject.Find("Canvas");

        var canvas = canvasObj.GetComponent<Canvas>();

        var canvasScaler = canvasObj.GetComponent<CanvasScaler>();

        float screen_w = Screen.width;

        float screen_h = Screen.height;

        var pos = transform.position;

        var fw = rtrans.rect.width;

        var fh = rtrans.rect.height;

        if (canvasScaler.uiScaleMode == CanvasScaler.ScaleMode.ScaleWithScreenSize)

        {

            screen_w = canvasScaler.referenceResolution.x;

            screen_h = screen_w * Screen.height / Screen.width;

        }

        if (canvas.renderMode == RenderMode.ScreenSpaceCamera)

        {

            fw = rtrans.rect.width / screen_w * cam_w;

            fh = rtrans.rect.height / screen_h * cam_h;

        }

        float[] wcs = new float[];

        var c1 = pos.x - fw / ;

        var c2 = pos.x + fw / ;

        var c3 = pos.y - fh / ;

        var c4 = pos.y + fh / ;

        //两种试计算得到的结果完全一样