topic Re: Best pratices to create and edit layer in .NET Forum

Best pratices to create and edit layer

seabrahenrique — Thu, 20 Oct 2022 12:33:12 GMT

Hello everyone!

I face two options here to create/edit layers in AutoCAD using C#. Which one is the better thinking about the good practices:

Access my LayerTable direct for write, like this:

LayerTable lytab = trans.GetObject(db.LayerTableId, OpenMode.ForWrite) as LayerTable; ....Create or update my layer

Or access my LaterTable for read, and use the instruction lytab.UpgradeOpen(), like this:

LayerTable lytab = trans.GetObject(db.LayerTableId, OpenMode.ForRead) as LayerTable; lytab.UpgradeOpen(); ....Create or update my layer

I know that result of both is equals, but one is better of other? (thinking about erros, performance and etc...)

Thanks in advance.

Re: Best pratices to create and edit layer

seabrahenrique — Thu, 20 Oct 2022 12:29:16 GMT

And a complementar question:

I really need this foreach simply to find a layer in my LayerTable?

LayerTable lytb = trans.GetObject(db.LayerTableId, OpenMode.ForRead) as LayerTable; foreach (ObjectId LyId in lytb) { LayerTableRecord ltbr = trans.GetObject(LyId, OpenMode.ForRead) as LayerTableRecord; if (ltbr.Name == "Teste") { ltbr.UpgradeOpen(); ltbr.Color = Color.FromColorIndex(ColorMethod.ByLayer, 3); LinetypeTable lttb = trans.GetObject(db.LinetypeTableId, OpenMode.ForRead) as LinetypeTable; if (lttb.Has("Hidden")) { ltbr.LinetypeObjectId = lttb["Hidden"]; } trans.Commit(); doc.Editor.WriteMessage("\nLayer alterado"); break; }

Or is there another simple way to set a layer in my LayerTableRecord if i know that name?

For example, in VBA i can do:

Dim MyLayer as AcadLayer MyLayer = ThisDrawing.Layer("NameOfLayer")

Can i do something similar in C# .NET to set a layer in a LayerTableRecord ltr, if i already know the name of layer is "NameOfLayer", for example?

Thanks again.

Re: Best pratices to create and edit layer

hippe013 — Thu, 20 Oct 2022 13:59:51 GMT

The get the layer objectId by name use the following:

(Sorry its in vb.net)

Dim lyrTbl As LayerTable = tr.GetObject(curDb.LayerTableId, OpenMode.ForRead) Dim lyrId As ObjectId = lyrTbl.Item("MyLayer")

Re: Best pratices to create and edit layer

norman.yuan — Thu, 20 Oct 2022 19:23:27 GMT

I am not sure what your were thinking of "best practice" with this code, where you have already known LayerTable.Has() method:

if you already know a block name ("Teste"), you simply do:

var layerTable=(LayerTable)tran.GetObject(db.LayerTableId, OpenMode.ForRead);

LayerTableRecord layer;

if (!layerTable.Has("Teste")

{

layerTable.UpgradeOpen();

layer=new LayerTableRecord();

layer.Name="Teste";

layerTable.Add(layer);

tran.AddNewlyCreatedDBObject(....);

}

else

{

layer=(LayerTableRecord)tran.GetObject(layerTable["Teste", OpenMode.ForWrite);

}

// Change/Set layer's properties here

layer.Color=...;

layer.LineType=....;

Because of the method Has(), there is no need to loop through LayerTable for each LayerTableRecord and test its name in order to find the layer in interest.

Re: Best pratices to create and edit layer

seabrahenrique — Mon, 24 Oct 2022 18:11:25 GMT

Thanks for the collaboration, guys!

I already found watt i need here.

Re: Best pratices to create and edit layer

hippe013 — Mon, 24 Oct 2022 19:12:29 GMT

If you found what you needed please mark the appropriate reply as the accepted solution. It helps others know that a solution has been found.

Re: Best pratices to create and edit layer

MarkJamesRogolino — Tue, 25 Oct 2022 05:42:53 GMT

Pls try this.

var documentManager = Application.DocumentManager; var currentDocument = documentManager.MdiActiveDocument; var database = currentDocument.Database; ObjectId layerId = ObjectId.Null; using (DocumentLock docLock = currentDocument.LockDocument()) { using (Transaction acTrans = database.TransactionManager.StartTransaction()) { // Open the Layer table for read LayerTable acLyrTbl; acLyrTbl = acTrans.GetObject(database.LayerTableId, OpenMode.ForRead) as LayerTable; LayerTableRecord acLyrTblRec = new LayerTableRecord(); acLyrTblRec.Name = "somename"; LinetypeTable acLinTbl; acLinTbl = acTrans.GetObject(database.LinetypeTableId, OpenMode.ForRead) as LinetypeTable; acLyrTbl.UpgradeOpen(); acLyrTbl.Add(acLyrTblRec); acTrans.AddNewlyCreatedDBObject(acLyrTblRec, true); acTrans.Commit(); } }

Re: Best pratices to create and edit layer

kerry_w_brown — Tue, 25 Oct 2022 19:40:45 GMT

@MarkJamesRogolino

Have you tested this code ?

what will happen if it's run twice ??

Re: Best pratices to create and edit layer

seabrahenrique — Sat, 29 Oct 2022 18:35:37 GMT

Sorry, but i can't use your suggestion, see:

The LayerTable object here does not have the .Item method... Again, someone know how can i get a layer by a name in C#?

In VBA i used to do this:

Dim MyLayer as AcadLayer MyLayer = ThisDrawing.Layer("NameOfLayer")

Is there a way to do something similar in .NET? I mean, if i already have the name of layer or block, can i access that using this name?

Re: Best pratices to create and edit layer

kerry_w_brown — Sat, 29 Oct 2022 19:38:53 GMT

Perhaps something like this :

public void GetLayerByName( ) { var db = Application.DocumentManager.MdiActiveDocument.Database; var layerName = "MyLayer"; using (var tr = db.TransactionManager.StartTransaction()) { var layerTable = (LayerTable)tr.GetObject( db.LayerTableId, OpenMode.ForRead); var layerRecord = (LayerTableRecord)tr.GetObject( layerTable[layerName], OpenMode.ForRead); // if you really want the ObjectID ?? var layerRecordOid = layerRecord.ObjectId; // . . . . } }

Regards,

Re: Best pratices to create and edit layer

kerry_w_brown — Sat, 29 Oct 2022 20:13:50 GMT

Of course, we should check that the LayerTable actually does have a Layer of that name 🙂

. . . or this will happen :

public void GetLayerByName( ) { var db = Application.DocumentManager.MdiActiveDocument.Database; var layerName = "MyLayer_DoesNotExist"; using ( var tr = db.TransactionManager.StartTransaction( ) ) { var layerTable = (LayerTable)tr.GetObject( db.LayerTableId, OpenMode.ForRead); // ensure the layer exists !! if ( !layerTable.Has( layerName ) ) { // show a message to the user. // then : return; } var layerRecord = (LayerTableRecord)tr.GetObject( layerTable[layerName], OpenMode.ForRead); // if you really want the ObjectID ?? var layerRecordOid = layerRecord.ObjectId; // . . . . } }

Re: Best pratices to create and edit layer

kerry_w_brown — Sat, 29 Oct 2022 22:14:57 GMT

For what it's worth ;

This is about 17 years old and posted more as proof of concept than professional code.

Making Layers with Particular Linetypes

Regards,