创建CRM应用程序时，我有错误

Question

[XamlCompilation(XamlCompilationOptions.Compile)]
public partial class MyPage : ContentPage
{
    AuthenticationResult authResult;
    private OrganizationDataWebServiceProxy proxy;
    public MyPage()
    {
        InitializeComponent();
        myButton.Clicked += MyButton_Clicked;
        proxy = new OrganizationDataWebServiceProxy();
    }
    async void MyButton_Clicked(object sender, EventArgs args)
    {
        try
        {
            var auth = DependencyService.Get<IAuthenticator>();
           authResult = await auth.Authenticate(Constants.Authority,
            Constants.ServiceURL,
            Constants.ClientId,
            Constants.RedirectURL,
            Constants.Username,
            Constants.Password);
        }
        catch(Exception ex)
        {
            await DisplayAlert("Error", "This: " + ex, "got it");
        }
        proxy.ServiceUrl = Constants.ServiceURL;
        proxy.AccessToken = authResult.AccessToken;
        await GetLoggedInUserName();
    }
    public async Task GetLoggedInUserName()
    {
        try
        {
            WhoAmIResponse result = (WhoAmIResponse)await proxy.Execute(new WhoAmIRequest());
            await DisplayAlert("Result n", "User Id : " + result.UserId.ToString() + "n OrganizationId: " + result.OrganizationId.ToString() + "n BusinessUnitId: " + result.BusinessUnitId.ToString(), "Ok", "Cancel");
        }
        catch (Exception ex)
        {
            await DisplayAlert("Error", "This: " + ex, "got it");
        }
    }
}

}

我收到此错误消息
1.当前文本中的名称LT不存在
2.当前文本中不存在名称AMP
3.当前文本中的名称GT不存在
4.authenticator是在给定上下文中无效的类型
有人请帮助我，我正要与Xamarin.forms一起制作CRM应用。Div>

该教程的作者由于HTML编码而在代码中存在一些错误，并且您复制了该错误。

更改线

var auth = DependencyService.Get<IAuthenticator>();

进入

var auth = DependencyService.Get<IAuthenticator>();