Make A Tiled Viewport Current (.NET)

You enter points and select objects in the current viewport. To make a viewport current, use the CVPORT system variable and specify the viewport by its number that you want to set current.

You can iterate through existing viewports to find a particular viewport. To do this, identify the Viewport table records with the name "*Active" using the Name property.

Split a viewport, then iterate through the windows

This example splits the active viewport into two horizontal windows. It then iterates through all the tiled viewports in the drawing and displays the viewport name and the lower-left and upper-right corner for each viewport.

C# Example

using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.DatabaseServices;
using Autodesk.AutoCAD.Runtime;
using Autodesk.AutoCAD.Geometry;
 
[CommandMethod("SplitAndIterateModelViewports")]
public static void SplitAndIterateModelViewports()
{
    // Get the current database
    Document acDoc = Application.DocumentManager.MdiActiveDocument;
    Database acCurDb = acDoc.Database;

    // Start a transaction
    using (Transaction acTrans = acCurDb.TransactionManager.StartTransaction())
    {
        // Open the Viewport table for write
        ViewportTable acVportTbl;
        acVportTbl = acTrans.GetObject(acCurDb.ViewportTableId,
                                        OpenMode.ForWrite) as ViewportTable;

        // Open the active viewport for write
        ViewportTableRecord acVportTblRec;
        acVportTblRec = acTrans.GetObject(acDoc.Editor.ActiveViewportId,
                                            OpenMode.ForWrite) as ViewportTableRecord;

        using (ViewportTableRecord acVportTblRecNew = new ViewportTableRecord())
        {
            // Add the new viewport to the Viewport table and the transaction
            acVportTbl.Add(acVportTblRecNew);
            acTrans.AddNewlyCreatedDBObject(acVportTblRecNew, true);

            // Assign the name '*Active' to the new Viewport
            acVportTblRecNew.Name = "*Active";

            // Use the existing lower left corner for the new viewport
            acVportTblRecNew.LowerLeftCorner = acVportTblRec.LowerLeftCorner;

            // Get half the X of the existing upper corner
            acVportTblRecNew.UpperRightCorner = new Point2d(acVportTblRec.UpperRightCorner.X,
                                                            acVportTblRec.LowerLeftCorner.Y +
                                                            ((acVportTblRec.UpperRightCorner.Y -
                                                              acVportTblRec.LowerLeftCorner.Y) / 2));

            // Recalculate the corner of the active viewport
            acVportTblRec.LowerLeftCorner = new Point2d(acVportTblRec.LowerLeftCorner.X,
                                                        acVportTblRecNew.UpperRightCorner.Y);

            // Update the display with the new tiled viewports arrangement
            acDoc.Editor.UpdateTiledViewportsFromDatabase();

            // Step through each object in the symbol table
            foreach (ObjectId acObjId in acVportTbl)
            {
                // Open the object for read
                ViewportTableRecord acVportTblRecCur;
                acVportTblRecCur = acTrans.GetObject(acObjId,
                                                        OpenMode.ForRead) as ViewportTableRecord;

                if (acVportTblRecCur.Name == "*Active")
                {
                    Application.SetSystemVariable("CVPORT", acVportTblRecCur.Number);

                    Application.ShowAlertDialog("Viewport: " + acVportTblRecCur.Number +
                                                " is now active." +
                                                "\nLower left corner: " +
                                                acVportTblRecCur.LowerLeftCorner.X + ", " +
                                                acVportTblRecCur.LowerLeftCorner.Y +
                                                "\nUpper right corner: " +
                                                acVportTblRecCur.UpperRightCorner.X + ", " +
                                                acVportTblRecCur.UpperRightCorner.Y);
                }
            }
        }

        // Commit the changes and dispose of the transaction
        acTrans.Commit();
    }
}