1.6、Lock and Unlock Layers锁定和解锁图层

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.

我们不能编辑已锁定图层上的对象，不过，如果已锁定图层是打开的并且是解冻的，那么图层上的对象仍然是可见的。我们可以将已锁定图层设为当前图层并往上添加对象，我们还可以冻结、关闭已锁定图层以及修改其关联的颜色和线型等。

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.

使用IsLocked属性来锁定或解锁图层。IsLocked属性值为TRUE则锁定图层，IsLocked属性值为FALSE则解锁图层。

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

本例创建一个名为“ABC”的新图层，然后将其锁定。

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"

Dim acLyrTblRec As LayerTableRecord

If acLyrTbl.Has(sLayerName) = False Then

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)

Else

acLyrTblRec = acTrans.GetObject(acLyrTbl(sLayerName),_

OpenMode.ForWrite)

End If

'' Lock the layer

acLyrTblRec.IsLocked = True

'' 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获取当前文档和数据库

Document acDoc = Application.DocumentManager.MdiActiveDocument;

Database acCurDb = acDoc.Database;

// Start a transaction启动事务

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

{

// Open the Layer table for read以读打开图层表

LayerTable acLyrTbl;

acLyrTbl = acTrans.GetObject(acCurDb.LayerTableId,OpenMode.ForRead) as LayerTable;

string sLayerName = "ABC";

LayerTableRecord acLyrTblRec;

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

{

acLyrTblRec = new LayerTableRecord();

// Assign the layer a name给图层名称赋值

acLyrTblRec.Name = sLayerName;

// Upgrade the Layer table for write升级打开图层表

acLyrTbl.UpgradeOpen();

// Append the new layer to the Layer table and the transaction追加新图层到图层表，追加事务记录

acLyrTbl.Add(acLyrTblRec);

acTrans.AddNewlyCreatedDBObject(acLyrTblRec,true);

}

else

{

acLyrTblRec = acTrans.GetObject(acLyrTbl[sLayerName],

OpenMode.ForWrite) as LayerTableRecord;

}

// Lock the layer锁定图层

acLyrTblRec.IsLocked = true;

// Save the changes and dispose of the transaction提交修改、关闭事务

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