Xamarin中的自定义事件页面c#

Question

我目前面临以下问题:

我试图在用户输入有效凭据时触发事件,以便我可以切换页面等等.

问题是由于某些原因我无法挂钩事件(虽然我很确定这会是一些愚蠢的事情).

发射事件的类:

namespace B2B
{

    public partial class LoginPage : ContentPage
    {
        public event EventHandler OnAuthenticated;

        public LoginPage ()
        {
            InitializeComponent ();
        }

        void onLogInClicked (object sender, EventArgs e)
        {
            loginActivity.IsRunning = true;

            errorLabel.Text = "";

            RestClient client = new RestClient ("http://url.be/api/");

            var request = new RestRequest ("api/login_check",  Method.POST);
            request.AddParameter("_username", usernameText.Text);
            request.AddParameter("_password", passwordText.Text);

            client.ExecuteAsync<Account>(request, response => {

                Device.BeginInvokeOnMainThread ( () => {
                    loginActivity.IsRunning = false;

                    if(response.StatusCode == HttpStatusCode.OK)
                    {
                        if(OnAuthenticated != null)
                        {
                            OnAuthenticated(this, new EventArgs());
                        }
                    }
                    else if(response.StatusCode == HttpStatusCode.Unauthorized)
                    {
                        errorLabel.Text = "Invalid Credentials";
                    }
                });

            });

        }
    }
}

并在'主类'

namespace B2B
{
    public class App : Application
    {
        public App ()
        {
            // The root page of your application
            MainPage = new LoginPage();

            MainPage.OnAuthenticated += new EventHandler (Authenticated);

        }

        static void Authenticated(object source, EventArgs e) {
            Console.WriteLine("Authed");
        }
    }
}

当我尝试构建应用程序时,我得到:

类型'Xamarin.Forms.Page'不包含'OnAuthenticated'的定义,也没有扩展方法OnAuthenticated

我已经尝试在LoginPage类中添加一个委托,但它没有帮助.

任何人都可以如此友善地指出我正在制造什么愚蠢的错误？

Answer 1

MainPage被定义为Xamarin.Forms.Page.这个类没有名为的属性OnAuthenticated.因此错误.LoginPage在分配之前,您需要将该实例存储在该类型的变量中,MainPage以便能够访问该类中定义的属性和方法:

var loginPage = new LoginPage();
loginPage.OnAuthenticated += new EventHandler(Authenticated); 
MainPage = loginPage;