Topic: Select Block by it's handle

[Conveyor1]

Morning,

Does anyone know how to select a block by it's handle?  I currently have some code I use to compare a dynamic blocks attributes currently in a drawing to what is in an excel file.  However, the code I have take a long time to run as it cycles thru every item in the blocktablerecord to find the block requiring the change.

Was looking for a more direct method as I have the block handle for the block needing the changes.

Please let me know when you can.

[gile]

Hi,

You can use the Database.GetObjectId() method, or better, the undocumented one: TryGetObjectId().

Code - C#: [Select]

1. if (db.TryGetObjectId(new Handle(Convert.ToInt64(someHandleString, 16)), out ObjectId id))
2.     // do what you need with id
3. else
4.     // the handle does not exist

[Atook]

I use a function like this to get an ObjectId

Code - C#: [Select]

1. /// <summary>
2. /// Given a handle, return an associated ObjectId
3. /// </summary>
4. /// <param name="handle">The handle.</param>
5. /// <returns>the required ObjectId or ObjectId.Null</returns>
6. public static ObjectId GetObjectIDFromHandle(string handle)
7. {
8.         if (handle.Length < 3) return ObjectId.Null;
9.         try
10.         {
11.                 // Convert hexadecimal string to 64-bit
12.                 long ln = Convert.ToInt64(handle, 16);
13.                 // Now create a Handle from the long integer
14.                 Handle hn = new Handle(ln);
15.                 // And attempt to get an ObjectId for the Handle
16.                 ObjectId id =Active.Database.GetObjectId(false,hn,0);
17.                 // return the objectID if it exists, ObjectId.Null if it doesn't
18.                 if (id.IsEffectivelyErased || id.IsErased) return ObjectId.Null;
19.                 return id;
20.         }
21.         catch
22.         {
23.                 return ObjectId.Null;
24.         }
25. }
26.  

I like Gile's TryGetObjectId method, but BricsCAD doesn't support it. Too bad, seems like a better method to me.

[gile]

@Atook, you can implement a TryGetObjectId extension method for BricsCAD, you can also overload it to directly take a string as argument

Code - C#: [Select]

1.     static class Extension
2.     {
3.         public static bool TryGetObjectId(this Database db, Handle handle, out ObjectId id)
4.         {
5.             try
6.             {
7.                 id = db.GetObjectId(false, handle, 0);
8.                 return true;
9.             }
10.             catch
11.             {
12.                 id = ObjectId.Null;
13.                 return false;
14.             }
15.         }
16.    
17.  
18.         public static bool TryGetObjectId(this Database db, string handle, out ObjectId id)
19.         {
20.             return db.TryGetObjectId(new Handle(Convert.ToInt64(handle, 16)), out id);
21.         }
22.     }

[Atook]

Many thanks Gile, I love seeing how you put things together!