如何在非活动类中使用Xamarin.Firebase.Auth并获得通知

Question

我想将FirebaseAuth封装到类AuthService中。

我也可以登录。。但是我无法从Firebase获取事件，因为它无法通知AuthService类中的侦听器。

当我从LoginActivity按下登录按钮时，我可以在控制台中看到用户已经登录

10-29 21:45:34.519 D/FirebaseAuth(28144(：通知id令牌侦听器有关用户的信息(mvBkX8YferS6XVdqUESLu2yldp2(。

10-29 21:45:34.527 D/FirebaseApp(28144(：通知身份验证状态侦听器。

10-29 21:45:34.528 D/FirebaseApp(28144(：已通知0个身份验证状态侦听器。

这是AuthService类：

public class AuthService : Java.Lang.Object, IOnSuccessListener, IOnFailureListener
{
public User CurrentUser;
private FirebaseAuth firebaseAuth;
private static AuthService _instance = null;
private static System.Object _mutex = new object();
public IntPtr Handle {get;}
public static AuthService GetInstance()
{
if (_instance == null)
{
lock (_mutex) // now I can claim some form of thread safety...
{
if (_instance == null)
{
_instance = new AuthService();
}
}
}
return _instance;
}
public AuthService()
{
Initialise();
}
private void Initialise()
{
this.firebaseAuth = FirebaseAuth.Instance;
if (FirebaseAuth.Instance.CurrentUser != null)
{
this.CurrentUser = User.GetInstance();
}
}
public FirebaseUser GetUser()
{
FirebaseUser user;
if (FirebaseAuth.Instance.CurrentUser != null)
{
user = FirebaseAuth.Instance.CurrentUser;
}
else
{
user = null;
}
return user;
}

public void SignInWithEmailAndPassword(string email, string password)
{
FirebaseAuth.Instance.SignInWithEmailAndPassword(email, password)
.AddOnSuccessListener(this)
.AddOnFailureListener(this);
}
public void OnSuccess(Java.Lang.Object result)
{
this.CurrentUser = User.GetInstance();
MyApplication.Context.StartActivity(typeof(MainActivity));
}
}
}

登录活动：

public class LoginActivity : Activity
{
AuthService _AuthService;
private EditText loginMail;
private EditText loginPassword;
private Button buttonLogin;
private Button buttonGoToCreateAccount;
protected override void OnCreate(Bundle savedInstanceState)
{
base.OnCreate(savedInstanceState);
SetContentView(Resource.Layout.activity_login);
loginMail = FindViewById<EditText>(Resource.Id.emaillogin);
loginPassword = FindViewById<EditText>(Resource.Id.passwordlogin);
buttonLogin = FindViewById<Button>(Resource.Id.loginbutton);
buttonLogin.Click += (sender, e) =>
{
AuthService.GetInstance().SignInWithEmailAndPassword(loginMail.Text, loginPassword.Text);
};
}
}

为什么在非活动类中实现的OnSuccess侦听器无法获取事件。我已经让FirebaseAuth直接从活动中工作，但我想封装身份验证。

有人有提示吗？

Answer 1

我终于做到了。

以下是身份验证的监听器类AuthListeners:

public class AuthListener : Java.Lang.Object, IOnSuccessListener, IOnFailureListener
{
public delegate void OnAuthFailure(string error);
public event OnAuthFailure OnAuthFailureEvent;
public delegate void OnAuthSuccess();
public event OnAuthSuccess OnAuthSuccessEvent;
public AuthListener()
{
}
public void OnSuccess(Java.Lang.Object result)
{
Console.WriteLine("success");
OnAuthSuccessEvent?.Invoke();
}
public void OnFailure(Java.Lang.Exception e)
{
Console.WriteLine("failure: " + e.Message);
OnAuthFailureEvent?.Invoke(e.Message);
}
}

这是AuthService类：

public class AuthService
{
private FirebaseAuth firebaseAuth;
public AuthService()
{
Initialise();
}
private void Initialise()
{
this.firebaseAuth = FirebaseAuth.Instance;
}    
public void SignInWithEmailAndPassword(string email, string password, AuthListener authListener)
{
FirebaseAuth.Instance.SignInWithEmailAndPassword(email, password)
.AddOnSuccessListener(authListener)
.AddOnFailureListener(authListener);
}
public void CreateUserWithEmailAndPassword(string email, string password, string userName, AuthListener authListener)
{
FirebaseAuth.Instance.CreateUserWithEmailAndPassword(email, password)
.AddOnFailureListener(authListener)
.AddOnSuccessListener(authListener);
}
public void SignOut()
{
FirebaseAuth.Instance.SignOut();
}
}

然后在登录|| create_account活动||片段中，我只调用Auth服务并从AuthListeners订阅事件。

登录活动示例：

public class LoginActivity : Activity
{
AuthListener _authListener;
AuthService _authService;
private EditText loginMail;
private EditText loginPassword;
private Button buttonLogin;
private Button buttonGoToCreateAccount;
protected override void OnCreate(Bundle savedInstanceState)
{
base.OnCreate(savedInstanceState);
SetContentView(Resource.Layout.activity_login);
_authListener = new AuthListener();
_authService = new AuthService();
Subscribe();
loginMail = FindViewById<EditText>(Resource.Id.emaillogin);
loginPassword = FindViewById<EditText>(Resource.Id.passwordlogin);
buttonLogin = FindViewById<Button>(Resource.Id.loginbutton);
buttonGoToCreateAccount = FindViewById<Button>(Resource.Id.goto_create_account);

buttonLogin.Click += (sender, e) =>
{
_authService.SignInWithEmailAndPassword(loginMail.Text, loginPassword.Text, this._authListener );
};
buttonGoToCreateAccount.Click += (sender, e) =>
{
UnSubscribe();
StartActivity(typeof(CreateAccountActivity));
Finish();
};
}
private void UnSubscribe()
{
_authListener.OnAuthFailureEvent -= ShowErrorDialog;
_authListener.OnAuthSuccessEvent -= AuthSuccess;
}
private void Subscribe()
{
_authListener.OnAuthFailureEvent += ShowErrorDialog;
_authListener.OnAuthSuccessEvent += AuthSuccess;
}
private void AuthSuccess()
{
StartActivity(typeof(DashboardActivity));
Finish();
}
private void ShowErrorDialog(string error)
{
this.RunOnUiThread(() =>
{
AlertDialog.Builder alertDialog = new AlertDialog.Builder(this);
alertDialog.SetTitle("Error");
alertDialog.SetMessage(error);
alertDialog.SetNeutralButton("Try again!", delegate
{
alertDialog.Dispose();
});
alertDialog.Show();
});
}
}

我现在可以声称我封装了Firebase Authenticate服务，所以如果有一天我最终想把Firebase留给另一个服务，那就不会一团糟，或者至少不会一团糟。