/// <summary>
/// Requires a transaction (not an OpenCloseTransaction) to be active when called:
/// Returns an enumeration of all AttributeDefinitions whose Constant property is
/// true, and all AttributeReferences attached to the block reference.
/// </summary>
public static IEnumerable <DBText> GetAttributes([NotNull] this BlockReference blockRef)
{
var tr = blockRef.GetTransaction();
var btr = (BlockTableRecord)blockRef.BlockTableRecord.GetObject(OpenMode.ForRead);
if (blockRef.AttributeCollection != null)
{
foreach (ObjectId id in blockRef.AttributeCollection)
{
if (id.IsValidEx())
{
continue;
}
yield return((AttributeReference)tr.GetObject(id, OpenMode.ForRead));
}
}
if (btr.HasAttributeDefinitions)
{
foreach (var id in btr)
{
if (!id.IsValidEx())
{
continue;
}
var attDef = tr.GetObject(id, OpenMode.ForRead) as AttributeDefinition;
if (attDef == null)
{
continue;
}
if (attDef.Constant)
{
yield return(attDef);
}
}
}
}