使层成为当前层 （.NET）

您始终在活动图层上绘图。激活图层时，将在该图层上创建新对象。如果将其他图层设置为活动状态，则会为您创建的任何新对象分配该新活动图层并使用其颜色和线型。如果图层处于冻结状态，则无法将其设置为活动状态。

要使图层处于活动状态，请使用对象的属性或 CLAYER 系统变量。例如：ClayerDatabase

使图层在数据库中成为当前

本示例使用属性设置通过对象的图层电流。DatabaseClayer

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

        If acLyrTbl.Has(sLayerName) = True Then
            '' Set the layer Center current
            acCurDb.Clayer = acLyrTbl(sLayerName)

            '' Save the changes
            acTrans.Commit()
        End If

        '' Dispose of the transaction
    End Using
End Sub

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

        if (acLyrTbl.Has(sLayerName) == true)
        {
            // Set the layer Center current
            acCurDb.Clayer = acLyrTbl[sLayerName];

            // Save the changes
            acTrans.Commit();
        }

        // Dispose of the transaction
    }
}

ThisDrawing.ActiveLayer = ThisDrawing.Layers("Center")

使用 CLAYER 系统变量使图层保持当前状态

本示例使用 CLAYER 系统变量设置层电流。

Application.SetSystemVariable("CLAYER", "Center")

Application.SetSystemVariable("CLAYER", "Center");

ThisDrawing.SetVariable "CLAYER", "Center"