public MainPageViewModel(IChatClient chatClient)
{
_chatClient = chatClient;
SendMessageCommand = Text.Select(s => !string.IsNullOrEmpty(s)).ToAsyncReactiveCommand();
SendMessageCommand.Subscribe(async() =>
{
var text = Text.Value;
Text.Value = null;
await _chatClient.CreateMessageAsync("0", text, UserId);
});
_chatClient.ObserveMessageCreated("0")
.Subscribe((message) => Messages.Add(message))
.AddTo(_disposable);
}