获取cad模型空间范围和图纸空间范围

就两个属性：

                Extmin and Extmax - Returns the extents of Model space.

                Pextmin and Pextmax - Returns the extents of the current Paper space layout.

下面是例子

 C#

[CommandMethod("ZoomExtents")]

static public void ZoomExtents()

{

// Zoom to the extents of the current space

Zoom(new Point3d(), new Point3d(), new Point3d(), 1.01075);

}

[CommandMethod("ZoomLimits")]

static public void ZoomLimits()

{

  Document acDoc = Application.DocumentManager.MdiActiveDocument;

  Database acCurDb = acDoc.Database;

  // Zoom to the limits of Model space

 Zoom(new Point3d(acCurDb.Limmin.X, acCurDb.Limmin.Y, 0), new Point3d  (acCurDb.Limmax.X , acCurDb.Limmax.Y,0), new Point3d(), 1);

}