topic Re: How to get the Handle of the CAD object ? in .NET Forum

How to get the Handle of the CAD object ?

Anonymous — Fri, 20 Oct 2017 01:58:17 GMT

Hello everyone！

I have a question of ObjectARX！

I want to get the Handle of the CAD object ?

who can help me?

sample or source!!

Re: How to get the Handle of the CAD object ?

kerry_w_brown — Fri, 20 Oct 2017 04:30:20 GMT

First

get the DBObject , call it say dbObj

Then

Handle dbObjHandle = dbObj.Handle;

String dbObjHandleString = dbObj.Handle.ToString();

Re: How to get the Handle of the CAD object ?

kerry_w_brown — Fri, 20 Oct 2017 04:39:25 GMT

And you may need these later

thanks to Jim Awe (from around 2004) published in the MgdDbg project.

https://github.com/ADN-DevTech/MgdDbg

       /// <summary>
       /// Converts a string value to a Handle object.
       /// </summary>
       /// <param name="strHandle"></param>
       /// <returns></returns>
       public static Handle
       StringToHandle (String strHandle)
       {
           Handle handle = new Handle();

           try
           {
               Int64 nHandle = Convert.ToInt64(strHandle, 16);
               handle = new Handle(nHandle);
           }
           catch (System.FormatException)
           {
           }
           return handle;
       }

       /// <summary>
       /// Gets the ObjectId that corresponds to the handle.
       /// </summary>
       /// <param name="db"></param>
       /// <param name="h"></param>
       /// <returns></returns>
       public static ObjectId
       HandleToObjectId (Database db, Handle h)
       {
           ObjectId id = ObjectId.Null;
           try
           {
               id = db.GetObjectId(false, h, 0);
           }
           catch (Autodesk.AutoCAD.Runtime.Exception x)
           {
               if (x.ErrorStatus != Autodesk.AutoCAD.Runtime.ErrorStatus.UnknownHandle)
               {
                   throw x;
               }
           }
           return id;
       }

Re: How to get the Handle of the CAD object ?

kerry_w_brown — Fri, 20 Oct 2017 04:53:20 GMT

Alternatively try

ObjectId.Handle;

using Autodesk.AutoCAD.Runtime;
using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.DatabaseServices;
 
[CommandMethod("StartTransactionManager")]
public static void StartTransactionManager()
{
    // 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 Block table for read
        BlockTable acBlkTbl;
        acBlkTbl = acTrans.GetObject(acCurDb.BlockTableId,
                                     OpenMode.ForRead) as BlockTable;
 
        // Open the Block table record Model space for read
        BlockTableRecord acBlkTblRec;
        acBlkTblRec = acTrans.GetObject(acBlkTbl[BlockTableRecord.ModelSpace],
                                        OpenMode.ForRead) as BlockTableRecord;
 
        // Step through the Block table record
        foreach (ObjectId asObjId in acBlkTblRec)
        {
            acDoc.Editor.WriteMessage("\nDXF name: " + asObjId.ObjectClass.DxfName);
            acDoc.Editor.WriteMessage("\nObjectID: " + asObjId.ToString());
            acDoc.Editor.WriteMessage("\nHandle: " + asObjId.Handle.ToString());
            acDoc.Editor.WriteMessage("\n");
        }
 
        // Dispose of the transaction
    }
}

Sample from

https://knowledge.autodesk.com/search-result/caas/CloudHelp/cloudhelp/2017/ENU/AutoCAD-NET/files/GUID-50FD6118-B2D1-4313-A7D6-830794DFDEFA-htm.html

Re: How to get the Handle of the CAD object ?

_gile — Fri, 20 Oct 2017 04:54:44 GMT

Hi,

You can directly get a Handle from an ObjectId using the ObjectId.Handle property.

There's an undocumented TryGetObjectId() method;

Database.TryGetObjectId(Handle h, out ObjectId id) -> bool

Re: How to get the Handle of the CAD object ?

kerry_w_brown — Fri, 20 Oct 2017 05:16:18 GMT

Hi Gilles

_gile wrote:

Hi,

You can directly get a Handle from an ObjectId using the ObjectId.Handle property.

Yes, I added that option in post 4 ... while you were posting your comment 🙂

Thanks for the reminder note about

the undocumented TryGetObjectId() method