Realm .NET string primary key is optional

[Per_Eriksson]

I have an iOS app written in Swift, that is using a full sync Realm stored in Realm Cloud.

When I look at the class “FullUser” in Realm Studio it looks like this:

uuid string (Primary Key)   
Id   int   
name string

I have also a .net class on the server that will access the same Realm.

C# code of class, (somewhat shortened):

    public class FullUser : RealmObject
    {
    [PrimaryKey]
    [MapTo("uuid")]
    public string Uuid { get; set; }

    [MapTo("id")]
    public int Id { get; set; }

    [MapTo("name")]
    public string Name { get; set; }
}

When I try to do a full sync in .net, I get error message:

ERROR: Connection[1]: Session[1]:
Failed to transform received changeset: Schema mismatch:
‘FullUser’ has primary key ‘uuid’, which is nullable on one side,
but not the other.

If I then look at my newly created, local synced Realm-file it looks like this:

uuid string? (Primary Key)   
Id   int   
name string?

For some reason, when I sync the Realm in .net
it makes the string properties optional in my local Realm.

How do I specify that I want my C#-code to create the string as
non nullable in my local Realm so it matches the one in the server so they can sync?

[nirinchev (Nikola Irinchev)]

Strings are implicitly nullable in .NET. If you want to make them non-nullable in the database, you should annotate the property with [Required].