当列数改变时，我需要在两个项目之间应用一个水平分隔线。因此，有必要在SizeChanged事件中获取此UWP AdaptativeGridView的列数。
AdaptiveGridView有一个“CalculateColumns”方法，但无法访问。
我尝试使用下面的代码进行计算，但没有达到预期效果：

var twoColumns = Math.Abs(AppWebsiteGridView.DesiredWidth - (AppWebsiteGridView.ActualWidth / 2));

        var oneColumn = Math.Abs(AppWebsiteGridView.ActualWidth - AppWebsiteGridView.DesiredWidth);

        var threeColumns = Math.Abs(AppWebsiteGridView.DesiredWidth - (AppWebsiteGridView.ActualWidth / 3));

        var numberOfItems = AppWebsiteGridView.Items.Count;

        if (AppWebsiteGridView.Items[numberOfItems - 1] is SignInModel lastItem && AppWebsiteGridView.Items[numberOfItems - 2] is SignInModel lastButOneItem
            && AppWebsiteGridView.Items[numberOfItems - 3] is SignInModel lastButTwoItem)
        {
            if (threeColumns < twoColumns)
            {
                lastItem.IsEndLine = false;
                lastButOneItem.IsEndLine = false;
                lastButTwoItem.IsEndLine = false;
            }

            else if (twoColumns < oneColumn)
            {
                lastItem.IsEndLine = false;
                lastButOneItem.IsEndLine = false;
                lastButTwoItem.IsEndLine = true;
            }

            else
            {
                lastItem.IsEndLine = false;
                lastButOneItem.IsEndLine = true;
                lastButTwoItem.IsEndLine = true;
            }