Lock and Unlock Layers (.NET)

You cannot edit objects on a locked layer; however, they are still visible if the layer is on and thawed. You can make a locked layer current and you can add objects to it. You can freeze and turn off locked layers and change their associated colors and linetypes.

Use the IsLocked property to lock or unlock a layer. If you input a value of TRUE, the layer is locked. If you input a value of FALSE, the layer is unlocked.

Lock a layer

This example creates a new layer called “ABC” and then locks the layer.

VB.NET

Imports Autodesk.AutoCAD.Runtime
Imports Autodesk.AutoCAD.ApplicationServices
Imports Autodesk.AutoCAD.DatabaseServices
 
<CommandMethod("LockLayer")> _
Public Sub LockLayer()
    '' 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 = "ABC"

        If acLyrTbl.Has(sLayerName) = False Then
            Using acLyrTblRec As LayerTableRecord = New LayerTableRecord()

                '' Assign the layer a name
                acLyrTblRec.Name = sLayerName

                '' Lock the layer
                acLyrTblRec.IsLocked = True

                '' Upgrade the Layer table for write
                acTrans.GetObject(acCurDb.LayerTableId, OpenMode.ForWrite)

                '' Append the new layer to the Layer table and the transaction
                acLyrTbl.Add(acLyrTblRec)
                acTrans.AddNewlyCreatedDBObject(acLyrTblRec, True)
            End Using
        Else
            Dim acLyrTblRec As LayerTableRecord = acTrans.GetObject(acLyrTbl(sLayerName), _
                                                                    OpenMode.ForWrite)

            '' Lock the layer
            acLyrTblRec.IsLocked = True
        End If

        '' Save the changes and dispose of the transaction
        acTrans.Commit()
    End Using
End Sub

C#

using Autodesk.AutoCAD.Runtime;
using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.DatabaseServices;
 
[CommandMethod("LockLayer")]
public static void LockLayer()
{
    // 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 = "ABC";

        if (acLyrTbl.Has(sLayerName) == false)
        {
            using (LayerTableRecord acLyrTblRec = new LayerTableRecord())
            {
                // Assign the layer a name
                acLyrTblRec.Name = sLayerName;

                // Lock the layer
                acLyrTblRec.IsLocked = true;

                // Upgrade the Layer table for write
                acTrans.GetObject(acCurDb.LayerTableId, OpenMode.ForWrite);

                // Append the new layer to the Layer table and the transaction
                acLyrTbl.Add(acLyrTblRec);
                acTrans.AddNewlyCreatedDBObject(acLyrTblRec, true);
            }
        }
        else
        {
            LayerTableRecord acLyrTblRec = acTrans.GetObject(acLyrTbl[sLayerName],
                                            OpenMode.ForWrite) as LayerTableRecord;

            // Lock the layer
            acLyrTblRec.IsLocked = true;
        }

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

VBA/ActiveX Code Reference

Sub LockLayer()
    ' Create a new layer called "ABC"
    Dim layerObj As AcadLayer
    Set layerObj = ThisDrawing.Layers.Add("ABC")
 
    ' Lock layer "ABC"
    layerObj.Lock = True
End Sub