任意の Block オブジェクトのメソッドおよびプロパティを使用して、ブロックを再定義します。ブロックを再定義すると、図面内のそのブロックへのすべての参照がすぐに更新され、新しい定義を反映します。
再定義は、再定義以前および以降のすべてのブロックの挿入に影響します。定数属性は失われ、新しい定数属性に置き換えられます。変数属性は、新しいブロックに属性がない場合でも変更されません。
次の例では、ブロックを定義し、その定義に円を追加します。次に、ブロック参照としてブロックを図面に挿入します。ブロック定義にある円を更新すると、ブロック参照が自動的に更新されます。
Imports Autodesk.AutoCAD.Runtime Imports Autodesk.AutoCAD.ApplicationServices Imports Autodesk.AutoCAD.DatabaseServices Imports Autodesk.AutoCAD.Geometry <CommandMethod("RedefiningABlock")> _ Public Sub RedefiningABlock() ' Get the current database and start a transaction Dim acCurDb As Autodesk.AutoCAD.DatabaseServices.Database acCurDb = Application.DocumentManager.MdiActiveDocument.Database Using acTrans As Transaction = acCurDb.TransactionManager.StartTransaction() ' Open the Block table for read Dim acBlkTbl As BlockTable acBlkTbl = acTrans.GetObject(acCurDb.BlockTableId, OpenMode.ForRead) If Not acBlkTbl.Has("CircleBlock") Then Using acBlkTblRec As New BlockTableRecord acBlkTblRec.Name = "CircleBlock" ' Set the insertion point for the block acBlkTblRec.Origin = New Point3d(0, 0, 0) ' Add a circle to the block Using acCirc As New Circle acCirc.Center = New Point3d(0, 0, 0) acCirc.Radius = 2 acBlkTblRec.AppendEntity(acCirc) acBlkTbl.UpgradeOpen() acBlkTbl.Add(acBlkTblRec) acTrans.AddNewlyCreatedDBObject(acBlkTblRec, True) ' Insert the block into the current space Using acBlkRef As New BlockReference(New Point3d(0, 0, 0), acBlkTblRec.Id) Dim acModelSpace As BlockTableRecord acModelSpace = acTrans.GetObject(acCurDb.CurrentSpaceId, OpenMode.ForWrite) acModelSpace.AppendEntity(acBlkRef) acTrans.AddNewlyCreatedDBObject(acBlkRef, True) MsgBox("CircleBlock has been created.") End Using End Using End Using Else ' Redefine the block if it exists Dim acBlkTblRec As BlockTableRecord = _ acTrans.GetObject(acBlkTbl.Item("CircleBlock"), OpenMode.ForWrite) ' Step through each object in the block table record For Each objID As ObjectId In acBlkTblRec Dim dbObj As DBObject = acTrans.GetObject(objID, OpenMode.ForRead) ' Revise the circle in the block If TypeOf dbObj Is Circle Then Dim acCirc As Circle = dbObj acCirc.UpgradeOpen() acCirc.Radius = acCirc.Radius * 2 End If Next ' Update existing block references For Each objID As ObjectId In acBlkTblRec.GetBlockReferenceIds(False, True) Dim acBlkRef As BlockReference = acTrans.GetObject(objID, OpenMode.ForWrite) acBlkRef.RecordGraphicsModified(True) Next MsgBox("CircleBlock has been revised.") End If ' Save the new object to the database acTrans.Commit() ' Dispose of the transaction End Using End Sub
using Autodesk.AutoCAD.Runtime; using Autodesk.AutoCAD.ApplicationServices; using Autodesk.AutoCAD.DatabaseServices; using Autodesk.AutoCAD.Geometry; [CommandMethod("RedefiningABlock")] public void RedefiningABlock() { // Get the current database and start a transaction Database acCurDb; acCurDb = Application.DocumentManager.MdiActiveDocument.Database; using (Transaction acTrans = acCurDb.TransactionManager.StartTransaction()) { // Open the Block table for read BlockTable acBlkTbl; acBlkTbl = acTrans.GetObject(acCurDb.BlockTableId, OpenMode.ForRead) as BlockTable; if (!acBlkTbl.Has("CircleBlock")) { using (BlockTableRecord acBlkTblRec = new BlockTableRecord()) { acBlkTblRec.Name = "CircleBlock"; // Set the insertion point for the block acBlkTblRec.Origin = new Point3d(0, 0, 0); // Add a circle to the block using (Circle acCirc = new Circle()) { acCirc.Center = new Point3d(0, 0, 0); acCirc.Radius = 2; acBlkTblRec.AppendEntity(acCirc); acBlkTbl.UpgradeOpen(); acBlkTbl.Add(acBlkTblRec); acTrans.AddNewlyCreatedDBObject(acBlkTblRec, true); // Insert the block into the current space using (BlockReference acBlkRef = new BlockReference(new Point3d(0, 0, 0), acBlkTblRec.Id)) { BlockTableRecord acModelSpace; acModelSpace = acTrans.GetObject(acCurDb.CurrentSpaceId, OpenMode.ForWrite) as BlockTableRecord; acModelSpace.AppendEntity(acBlkRef); acTrans.AddNewlyCreatedDBObject(acBlkRef, true); Application.ShowAlertDialog("CircleBlock has been created."); } } } } else { // Redefine the block if it exists BlockTableRecord acBlkTblRec = acTrans.GetObject(acBlkTbl["CircleBlock"], OpenMode.ForWrite) as BlockTableRecord; // Step through each object in the block table record foreach (ObjectId objID in acBlkTblRec) { DBObject dbObj = acTrans.GetObject(objID, OpenMode.ForRead) as DBObject; // Revise the circle in the block if (dbObj is Circle) { Circle acCirc = dbObj as Circle; acCirc.UpgradeOpen(); acCirc.Radius = acCirc.Radius * 2; } } // Update existing block references foreach (ObjectId objID in acBlkTblRec.GetBlockReferenceIds(false, true)) { BlockReference acBlkRef = acTrans.GetObject(objID, OpenMode.ForWrite) as BlockReference; acBlkRef.RecordGraphicsModified(true); } Application.ShowAlertDialog("CircleBlock has been revised."); } // Save the new object to the database acTrans.Commit(); // Dispose of the transaction } }
Sub RedefiningABlock() ' Define the block Dim blockObj As AcadBlock Dim insertionPnt(0 To 2) As Double insertionPnt(0) = 0 insertionPnt(1) = 0 insertionPnt(2) = 0 On Error Resume Next Set blockObj = Blocks("CircleBlock") Err.Clear If blockObj Is Nothing Then Set blockObj = ThisDrawing.Blocks.Add(insertionPnt, "CircleBlock") ' Add a circle to the block Dim circleObj As AcadCircle Dim center(0 To 2) As Double Dim radius As Double center(0) = 0 center(1) = 0 center(2) = 0 rad = 2 Set circleObj = blockObj.AddCircle(center, rad) ' Insert the block Dim blockRefObj As AcadBlockReference insertionPnt(0) = 0 insertionPnt(1) = 0 insertionPnt(2) = 0 Set blockRefObj = ThisDrawing.ActiveLayout.Block.InsertBlock(insertionPnt, "CircleBlock", 1, 1, 1, 0) Else Set blockObj = ThisDrawing.Blocks.Item("CircleBlock") Dim acObj As AcadObject ' Redefine the circle objects in the block For Each acObj In blockObj If TypeOf acObj Is AcadCircle Then Dim acCirc As AcadCircle Set acCirc = acObj acCirc.radius = acCirc.radius * 2 End If Next ' Update the blocks in the drawing Regen acAllViewports End If End Sub