private void AssociateLevelTo3DView(Level level, View3D view)
{
SchemaBuilder builder = new SchemaBuilder(Guids.THREE_D_VIEW_SHEMA_GUID);
builder.SetReadAccessLevel(AccessLevel.Public);
builder.SetWriteAccessLevel(AccessLevel.Public);
builder.SetSchemaName("AssociatedLevel");
builder.SetDocumentation("Associated level");
// Create field1
FieldBuilder fieldBuilder1 = builder.AddSimpleField("Level", typeof(ElementId));
// Register the schema object
Schema schema = builder.Finish();
Field levelId = schema.GetField("Level");
Entity ent = new Entity(schema);
ent.Set(levelId, level.Id);
view.SetEntity(ent);
}