Unity3d讓GridLayoutGroup按照子物體的數量自動調整寬高

    /// <summary>
    /// 設置GridLayoutGroup的寬高
    /// </summary>
    /// <param name="grid">需要調整寬高的GridLayoutGroup</param>
    private void AutoGridLayoutSize(GridLayoutGroup grid)
    {
        int num = grid.constraintCount;//每行/列Cell約束的個數
        int k = (grid.transform.childCount + num - 1) / num;
        float value;
        RectTransform.Axis axis;
        switch (grid.constraint)
        {
            case GridLayoutGroup.Constraint.FixedColumnCount:
                value = k * grid.cellSize.y;//列數乘以Cell的高度
                value += (k - 1) * grid.spacing.y;//每列之間有間隔
                value += grid.padding.top + grid.padding.bottom;//上下間隔
                axis = RectTransform.Axis.Vertical;
                break;
            case GridLayoutGroup.Constraint.FixedRowCount:
                value = k * grid.cellSize.x;//行數乘以Cell的高度
                value += (k - 1) * grid.spacing.x;//每行之間有間隔
                value += grid.padding.left + grid.padding.right;//左右間隔
                axis = RectTransform.Axis.Horizontal;
                break;
            default:
                Debug.LogError(grid.name + "的約束為：Flexibl！");
                return;
        }
        (grid.transform as RectTransform).SetSizeWithCurrentAnchors(axis, value);
    }