LoginModel.cs

public class LoginModel : ObservableObject
{
	private string _username;
	public string Username
	{
	    get { return _username; }
	    set {
	        _username = value;
	        SetProperty(ref _username, value);
	    }
	}
	private string _password;
	public string Password
	{
	    get { return _password; }
	    set {
	        _password = value;
	        SetProperty(ref _password, value);
	    }
	}
}