Freeze and Thaw Layers (.NET)

You can freeze layers to speed up display changes, improve object selection performance, and reduce regeneration time for complex drawings. AutoCAD does not display, plot, or regenerate objects on frozen layers. Freeze the layers that you will not be working with for long periods of time. When you “thaw” a frozen layer, AutoCAD regenerates and displays the objects on that layer.

Use the IsFrozen property to freeze or thaw a layer. If you input a value of TRUE, the layer is frozen. If you input a value of FALSE, the layer is thawed.

Freeze a layer

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

VB.NET

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

                '' 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)

                '' Freeze the layer
                acLyrTblRec.IsFrozen = True
            End Using
        Else
            Dim acLyrTblRec As LayerTableRecord = acTrans.GetObject(acLyrTbl(sLayerName), _
                                                                    OpenMode.ForWrite)

            '' Freeze the layer
            acLyrTblRec.IsFrozen = 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("FreezeLayer")]
public static void FreezeLayer()
{
    // 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;

                // 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);

                // Freeze the layer
                acLyrTblRec.IsFrozen = true;
            }
        }
        else
        {
            LayerTableRecord acLyrTblRec = acTrans.GetObject(acLyrTbl[sLayerName],
                                            OpenMode.ForWrite) as LayerTableRecord;

            // Freeze the layer
            acLyrTblRec.IsFrozen = true;
        }

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

VBA/ActiveX Code Reference

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