private async void SubmitButton_Clicked(object sender, EventArgs e)
{
if (string.IsNullOrWhiteSpace(userNameEntry.Text) || string.IsNullOrWhiteSpace(passwordEntry.Text))
{
await DisplayAlert("Log In", "Enter Login and Password", "OK");
}
else
{
IvalidateUser validator = new ValidateUser();
bool result = await validator.AuthenticationUser(userNameEntry.Text, passwordEntry.Text);
if (result)
{
await DisplayAlert("Log In", "Login is successful", "OK");
await Navigation.PushAsync(new UsersViewPage());
}
else
{
await DisplayAlert("Log In", "Login or password is incorected", "OK");
}
}
}