From the signature, I guess that function "translate" a pixel on the screen to a coordinate in th the drawing. So I guess you would call this method twice, with bottom-left and top-right pixel. That would give you the area of the drawing currently displayed.
However, as you mentionned, I don't know of any way to get the two interesting pixels...
I used to have this "prototype" code, but somehow I never could make it work:
{code}
// This code was meant to get the real displayed area.
using (Transaction transaction = Application.DocumentManager.MdiActiveDocument.TransactionManager.StartTransaction())
{
ViewportTable viewportTable = (ViewportTable)transaction.GetObject(Application.DocumentManager.MdiActiveDocument.Database.ViewportTableId, OpenMode.ForRead);
ObjectId viewportId = viewportTable["*Active"];
if (viewportId.IsNull)
{
log.Debug("Could not find active Viewport");
return;
}
ViewportTableRecord viewport = (ViewportTableRecord)transaction.GetObject(viewportId, OpenMode.ForRead);
log.Debug(string.Format("Viewport: center={0} height={1} width={2}", viewport.CenterPoint, viewport.Height, viewport.Width));
}
{code}