Repository.cs

Repository.cs

protected virtual object[] GetKeysValues(TEntity entity)
{
    var entry = Context.Entry(entity);
    return entry.Metadata.FindPrimaryKey()
                 .Properties
                 .Select(p => entry.Property(p.Name).CurrentValue)
                 .ToArray();
}

public string GenerateEntityId(TEntity entity)
{
    return String.Join('$', this.GetKeysValues(entity));
}