仅获取屏幕上范围的范围坐标

我目前正在使用以下方法来查找a的坐标Range在文档中：

private Rectangle GetRangeCoordinates(Window w, Range r)
{
    int left = 0;
    int top = 0;
    int width = 0;
    int height = 0;

    w.GetPoint(out left, out top, out width, out height, r);

    return new Rectangle(left, top, width, height);
}

这非常有效，除非Range超出屏幕相当大的边距（相当多页），在这种情况下，我会得到以下异常：

System.Runtime.InteropServices.COMException（0x800A1066）：命令 在 Microsoft.Office.Interop.Word.Window.GetPoint(Int32& ScreenPixelsLeft、Int32& ScreenPixelsTop、Int32& ScreenPixelsWidth、 Int32& ScreenPixelsHeight，对象 obj) at[项目名称].[任务窗格名称].GetRange 坐标（窗口，范围 r） in[...somePath...][任务窗格名称].cs:线 66

有没有办法判断是否Range是否在屏幕上，以便我只能在屏幕上时调用此方法？

我就是这样做的。

我创建了一些扩展方法Application and Range:

public static class ApplicationExensions
{
    // more (rather than less)
    // does not do headers and footers
    public static Range GetCurrentlyVisibleRange(this Application application)
    {
        try
        {
            Window activeWindow = application.ActiveWindow;
            var left = application.PointsToPixels(activeWindow.Left);
            var top = application.PointsToPixels(activeWindow.Top);
            var width = application.PointsToPixels(activeWindow.Width);
            var height = application.PointsToPixels(activeWindow.Height);
            var usableWidth = application.PointsToPixels(activeWindow.UsableWidth);
            var usableHeight = application.PointsToPixels(activeWindow.UsableHeight);

            var startRangeX = left;// + (width - usableWidth);
            var startRangeY = top;// + (height - usableHeight);

            var endRangeX = startRangeX + width;//usableWidth;
            var endRangeY = startRangeY + height;//usableHeight;

            Range start = (Range) activeWindow.RangeFromPoint((int) startRangeX, (int) startRangeY);
            Range end = (Range) activeWindow.RangeFromPoint((int) endRangeX, (int) endRangeY);

            Range r = application.ActiveDocument.Range(start.Start, end.Start);

            return r;
        }
        catch (COMException)
        {
            return null;
        }
    }
}

public static class RangeExtensions
{
    public static bool Intersects(this Range a, Range b)
    {
        return a.Start <= b.End && b.Start <= a.End;
    }

    public static Rectangle? GetCoordinates(this Range range)
    {
        try
        {
            Application application = range.Application;
            Window window = application.ActiveWindow;

            int left = 0;
            int top = 0;
            int width = 0;
            int height = 0;

            window.GetPoint(out left, out top, out width, out height, range);

            return new Rectangle(left, top, width, height);
        }
        catch (COMException e)
        {
            return null;
        }
    }
}

然后我像这样使用它们：

Range currentlyVisibleRange = application.GetCurrentlyVisibleRange();

if (currentlyVisibleRange.Intersects(rng)){
    var coords = rng.GetCoordinates();
}