cad.net创建新图层

using Autodesk.AutoCAD.Runtime;

using Autodesk.AutoCAD.ApplicationServices;

using Autodesk.AutoCAD.DatabaseServices;

using Autodesk.AutoCAD.EditorInput;

using Autodesk.AutoCAD.Colors;

 

namespace LayerCreation

{

  public class Commands

  {

    // For fun let's assign each new layer with a new colour

 

    static short _colorIndex = 0;

 

    [CommandMethod("CL")]

    public void CreateLayer()

    {

      Document doc =

        Application.DocumentManager.MdiActiveDocument;

      Database db = doc.Database;

      Editor ed = doc.Editor;

 

      Transaction tr =

        db.TransactionManager.StartTransaction();

      using (tr)

      {

        // Get the layer table from the drawing

 

        LayerTable lt =

          (LayerTable)tr.GetObject(

            db.LayerTableId,

            OpenMode.ForRead

          );

 

        // Check the layer name, to see whether it's

        // already in use

 

        PromptStringOptions pso =

          new PromptStringOptions(

            "\nEnter new layer name: "

          );

        pso.AllowSpaces = true;

 

        // A variable for the layer name

 

        string layName = "";

 

        do

        {

          PromptResult pr = ed.GetString(pso);

 

          // Just return if the user cancelled

          // (will abort the transaction as we drop out of the using

          // statement's scope)

 

          if (pr.Status != PromptStatus.OK)

            return;

 

          try

          {

            // Validate the provided symbol table name

 

            SymbolUtilityServices.ValidateSymbolName(

              pr.StringResult,

              false

            );

 

            // Only set the layer name if it isn't in use

 

            if (lt.Has(pr.StringResult))

              ed.WriteMessage(

                "\nA layer with this name already exists."

              );

            else

              layName = pr.StringResult;

          }

          catch

          {

            // An exception has been thrown, indicating the

            // name is invalid

 

            ed.WriteMessage(

              "\nInvalid layer name."

            );

          }

 

        } while (layName == "");

 

        // Create our new layer table record...

 

        LayerTableRecord ltr = new LayerTableRecord();

 

        // ... and set its properties

 

        ltr.Name = layName;

        ltr.Color =

          Color.FromColorIndex(ColorMethod.ByAci, _colorIndex);

 

        // Add the new layer to the layer table

 

        lt.UpgradeOpen();

        ObjectId ltId = lt.Add(ltr);

        tr.AddNewlyCreatedDBObject(ltr, true);

 

        // Set the layer to be current for this drawing

 

        db.Clayer = ltId;

 

        // Commit the transaction

 

        tr.Commit();

 

        // Report what we've done

 

        ed.WriteMessage(

          "\nCreated layer named \"{0}\" with " +

          "a color index of {1}.",

          layName, _colorIndex++

        );

      }

    }

  }

}