Reallm .Net Linq String Operations - realm

Question

I have a list of location codes that are a concatenation of BUILDING/ROOM i.e. "BLD23223019" where the first 5 characters are the building. I split building code from the string and display it in one list for the user to select which then takes the user to a list of rooms within that building. So I pass the building code to the Room list to filter the rooms and I do this like:
_realm = Realm.GetInstance(RealmInstance.RealmPath);
try
{
_locations = _realm.All<Building>().Where(x => x.BuildingCode.Contains(_room.RoomCode)).ToList();
}
catch (Exception e)
{
Console.WriteLine(e);
throw;
}
ListViewLocations.ItemsSource = _locations;
but it doesn't give me any results, instead I get a target invocation error and the inner exception is "This object belongs to a closed realm." This also happens if I use "Equals(_room.RoomCode). I can't understand why the realm would be closed just from the above code.
I'm new to Realm so maybe I'm doing something wrong, if anyone can point me in the right direction it would be much appreciated.
This is the inner exception that the above code throws
at Realms.NativeException.ThrowIfNecessary (System.Func`2[T,TResult]
overrider) [0x0000a] in
/Users/realm/jenkins/workspace/realm_realm-dotnet_PR-1775/Realm/Realm/Native/NativeException.cs:57
at Realms.MarshalHelpers.GetString
(Realms.MarshalHelpers+NativeCollectionGetter getter) [0x0002b] in
/Users/realm/jenkins/workspace/realm_realm-dotnet_PR-1775/Realm/Realm/MarshalHelpers.cs:55
at Realms.ObjectHandle.GetString (System.IntPtr propertyIndex)
[0x00013] in
/Users/realm/jenkins/workspace/realm_realm-dotnet_PR-1775/Realm/Realm/Handles/ObjectHandle.cs:258
at Realms.RealmObject.GetStringValue (System.String propertyName)
[0x00000] in
/Users/realm/jenkins/workspace/realm_realm-dotnet_PR-1775/Realm/Realm/RealmObject.cs:139
at AsssetMan.Models.Buildings.get_BuildingCode () [0x00014] in
D:\Projects\AssetManRealm\AssetMan\AssetMan\Models\Buildings.cs:8
at (wrapper managed-to-native)
System.Reflection.MonoMethod.InternalInvoke(System.Reflection.MonoMethod,object,object[],System.Exception&)
at System.Reflection.MonoMethod.Invoke (System.Object obj,
System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder
binder, System.Object[] parameters, System.Globalization.CultureInfo
culture) [0x00032] in <43dbbdc147f2482093d8409abb04c233>:0

Answer 1

Thanks to #mjwills I've figured it out. the first comment using var bob in the linq extension worked if I used a literal. That meant there had to be a problem with the variable or the way I was passing the BuildingCode to the RoomCode page. The message "Realm is closed", or something to that effect, had me stumped at first then I remembered that the Realm objects are "Live" and as I was closing the _realm on the previous page, the building object I was passing to the RoomCode page was no longer available. So I new'd up a building object and when the building was selected from the list of buildings, copied the building code into it and passed that to the lookup for the RoomCode so the BuildingCode was still available after the Realm is closed.
Thanks #mjwills.