/// <summary>
/// Handle login process if user press login button
/// </summary>
/// <returns></returns>
async void HandleLoginAsync()
{
if (appcore.AuthUser(this.Username, this.Password))
{
await page.Navigation.PushAsync(new ChangeWorklocation());
}
else
{
await page.DisplayAlert("Login fehlgeschlagen", "Username oder Passwort falsch", "Ok");
}
}