Detach Xrefs (.NET)

You can detach an xref definition to remove the xrefs completely from your drawing. You can also erase the individual xref instances. Detaching the xref definition removes all dependent symbols associated with that xref. If all the instances of an xref are erased from the drawing, AutoCAD removes the xref definition the next time the drawing is opened.

To detach an xref, use the DetachXref method. You cannot detach a nested xref.

Detach an xref definition

This example attaches an external reference and then detaches the external reference. This example uses the Exterior Elevations.dwg file found in the Sample directory. If you do not have this image, or if it is located in a different directory, insert a valid path and file name.

C# Example

using Autodesk.AutoCAD.Runtime;
using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.DatabaseServices;
using Autodesk.AutoCAD.Geometry;

[CommandMethod("DetachingExternalReference")]
public void DetachingExternalReference()
{
    // Get the current database and start a transaction
    Database acCurDb;
    acCurDb = Application.DocumentManager.MdiActiveDocument.Database;

    using (Transaction acTrans = acCurDb.TransactionManager.StartTransaction())
    {
        // Create a reference to a DWG file
        string PathName = "C:\\AutoCAD\\Sample\\Sheet Sets\\Architectural\\Res\\Exterior Elevations.dwg";
        ObjectId acXrefId = acCurDb.AttachXref(PathName, "Exterior Elevations");

        // If a valid reference is created then continue
        if (!acXrefId.IsNull)
        {
            // Attach the DWG reference to the current space
            Point3d insPt = new Point3d(1, 1, 0);
            using (BlockReference acBlkRef = new BlockReference(insPt, acXrefId))
            {
                BlockTableRecord acBlkTblRec;
                acBlkTblRec = acTrans.GetObject(acCurDb.CurrentSpaceId, OpenMode.ForWrite) as BlockTableRecord;

                acBlkTblRec.AppendEntity(acBlkRef);
                acTrans.AddNewlyCreatedDBObject(acBlkRef, true);
            }

            Application.ShowAlertDialog("The external reference is attached.");

            acCurDb.DetachXref(acXrefId);

            Application.ShowAlertDialog("The external reference is detached.");
        }

        // Save the new objects to the database
        acTrans.Commit();

        // Dispose of the transaction
    }
}