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.
This example creates a new layer called “ABC” and then locks the layer.
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();
}
}