private async void ReceiveMessages(object sender, EventArgs e)
{
IEnumerable <Message> messages = (await clientService.ReceiveMessages()).OrderBy(x => x.PostDate);
IEnumerable <string> interlocutors = ChatTabs.Select(x => x.Interlocutor);
foreach (Message message in messages)
{
if (!interlocutors.Contains(message.Sender))
{
ChatTabs.Add(new ChatTabViewModel(message.Sender, clientService));
}
ChatTabs.Single(x => x.Interlocutor == message.Sender).Messages.Add(message);
}
}
