Create and Name Layers

You can create new layers and assign color and linetype properties to those layers. Each individual layer is part of the Layers table. Use the Add function to create a new layer and add it to the Layers table.

You can assign a name to a layer when it is created. To change the name of a layer after it has been created, use the Name property. Layer names can include up to 255 characters and contain letters, digits, and the special characters dollar sign ($), hyphen (-), and underscore (_).

For more information about creating layers, see “Create and Name Layers” in the AutoCAD User's Guide.

Create a new layer, assign it the color red, and add an object to the layer

The following code creates a new layer and circle object. The new layer is assigned the color red. The circle is assigned to the layer, and the color of the circle changes accordingly.

VB.NET

Imports Autodesk.AutoCAD.Runtime

Imports Autodesk.AutoCAD.ApplicationServices

Imports Autodesk.AutoCAD.DatabaseServices

Imports Autodesk.AutoCAD.Geometry

Imports Autodesk.AutoCAD.Colors

<CommandMethod("CreateAndAssignALayer")> _

Public Sub CreateAndAssignALayer()

  '' Get the current document and database

  Dim acDoc As Document = Application.DocumentManager.MdiActiveDocument

  Dim acCurDb As Database = acDoc.Database

  '' Start a transaction

  Using acTrans As Transaction = acCurDb.TransactionManager.StartTransaction()

      '' Open the Layer table for read

      Dim acLyrTbl As LayerTable

      acLyrTbl = acTrans.GetObject(acCurDb.LayerTableId, _

                                   OpenMode.ForRead)

      Dim sLayerName As String = "Center"

      If acLyrTbl.Has(sLayerName) = False Then

          Dim acLyrTblRec As LayerTableRecord = New LayerTableRecord()

          '' Assign the layer the ACI color 1 and a name

          acLyrTblRec.Color = Color.FromColorIndex(ColorMethod.ByAci, 1)

          acLyrTblRec.Name = sLayerName

          '' Upgrade the Layer table for write

          acLyrTbl.UpgradeOpen()

          '' Append the new layer to the Layer table and the transaction

          acLyrTbl.Add(acLyrTblRec)

          acTrans.AddNewlyCreatedDBObject(acLyrTblRec, True)

      End If

      '' Open the Block table for read

      Dim acBlkTbl As BlockTable

      acBlkTbl = acTrans.GetObject(acCurDb.BlockTableId, _

                                   OpenMode.ForRead)

      '' Open the Block table record Model space for write

      Dim acBlkTblRec As BlockTableRecord

      acBlkTblRec = acTrans.GetObject(acBlkTbl(BlockTableRecord.ModelSpace), _

                                      OpenMode.ForWrite)

      '' Create a circle object

      Dim acCirc As Circle = New Circle()

      acCirc.Center = New Point3d(2, 2, 0)

      acCirc.Radius = 1

      acCirc.Layer = sLayerName

      acBlkTblRec.AppendEntity(acCirc)

      acTrans.AddNewlyCreatedDBObject(acCirc, True)

      '' Save the changes and dispose of the transaction

      acTrans.Commit()

  End Using

End Sub

using Autodesk.AutoCAD.Runtime;

using Autodesk.AutoCAD.ApplicationServices;

using Autodesk.AutoCAD.DatabaseServices;

using Autodesk.AutoCAD.Geometry;

using Autodesk.AutoCAD.Colors;

[CommandMethod("CreateAndAssignALayer")]

public static void CreateAndAssignALayer()

  // Get the current document and database

  Document acDoc = Application.DocumentManager.MdiActiveDocument;

  Database acCurDb = acDoc.Database;

  // Start a transaction

  using (Transaction acTrans = acCurDb.TransactionManager.StartTransaction())

      // Open the Layer table for read

      LayerTable acLyrTbl;

      acLyrTbl = acTrans.GetObject(acCurDb.LayerTableId,

                                   OpenMode.ForRead) as LayerTable;

      string sLayerName = "Center";

      if (acLyrTbl.Has(sLayerName) == false)

          LayerTableRecord acLyrTblRec = new LayerTableRecord();

          // Assign the layer the ACI color 1 and a name

          acLyrTblRec.Color = Color.FromColorIndex(ColorMethod.ByAci, 1);

          acLyrTblRec.Name = sLayerName;

          // Upgrade the Layer table for write

          acLyrTbl.UpgradeOpen();

          // Append the new layer to the Layer table and the transaction

          acLyrTbl.Add(acLyrTblRec);

          acTrans.AddNewlyCreatedDBObject(acLyrTblRec, true);

      // Open the Block table for read

      BlockTable acBlkTbl;

      acBlkTbl = acTrans.GetObject(acCurDb.BlockTableId,

                                   OpenMode.ForRead) as BlockTable;

      // Open the Block table record Model space for write

      BlockTableRecord acBlkTblRec;

      acBlkTblRec = acTrans.GetObject(acBlkTbl[BlockTableRecord.ModelSpace],

                                      OpenMode.ForWrite) as BlockTableRecord;

      // Create a circle object

      Circle acCirc = new Circle();

      acCirc.Center = new Point3d(2, 2, 0);

      acCirc.Radius = 1;

      acCirc.Layer = sLayerName;

      acBlkTblRec.AppendEntity(acCirc);

      acTrans.AddNewlyCreatedDBObject(acCirc, true);

      // Save the changes and dispose of the transaction

      acTrans.Commit();

VBA/ActiveX Code Reference