Question

我想在用户第一次登录时显示alertdialog（我正在使用firebase身份验证）。有关如何做到这一点的任何想法？我尝试使用SharedPreferences，但只是在应用程序第一次在设备上运行时显示alertdialog。我希望它是特定于用户的，以便在他们第一次登录时为每个用户显示alertdialog。

Answer 1

一种方法是在登录活动上调用finish（）之前显示对话框。另一种方法是检查FirebaseAuth.getInstance（）。getCurrentUser（）是否不返回null，然后从您刚刚调用它的活动中显示该对话框。在此之后，您将在与用户ID关联的首选项中显示＆＃34;警告显示＆＃34; -flag，并在显示警报之前检查其是否存在。

我很抱歉没有更具体。如果您想要更准确的答案，请发布您的代码。

Answer 2

在onActivityResult中，您可以显示progressDialog这样的内容。

@Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);

    // Result returned from launching the Intent from GoogleSignInApi.getSignInIntent(...);
    if (requestCode == RC_SIGN_IN) {
        GoogleSignInResult result = Auth.GoogleSignInApi.getSignInResultFromIntent(data);
        if (result.isSuccess()) {
            // Google Sign In was successful, authenticate with Firebase
            GoogleSignInAccount account = result.getSignInAccount();
            progress = new ProgressDialog(this);
            progress.setMessage("Connecting Please Wait!..");
            progress.setProgressStyle(ProgressDialog.STYLE_SPINNER);
            progress.setIndeterminate(false);
            progress.show();
            firebaseAuthWithGoogle(account);
        } else {
            // Google Sign In failed, update UI appropriately
            // ...
        }
    }
}

并且firebaseAuthWithGoogle(GoogleSignInAccount account)函数是

private void firebaseAuthWithGoogle(GoogleSignInAccount acct) {
        Log.d(TAG, "firebaseAuthWithGoogle:" + acct.getId());

    AuthCredential credential = GoogleAuthProvider.getCredential(acct.getIdToken(), null);
    mAuth.signInWithCredential(credential)
            .addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
                @Override
                public void onComplete(@NonNull Task<AuthResult> task) {
                    if (task.isSuccessful()) {
                        progress.cancel();
                        // Sign in success, update UI with the signed-in user's information 
//and here you can use your sharedPreference for that Account.
                            Log.d(TAG, "signInWithCredential:success");
                        } else {
                            // If sign in fails, display a message to the user.
                            Log.w(TAG, "signInWithCredential:failure", task.getException());
                        Toast.makeText(MainActivity.this, "Authentication failed.",
                                Toast.LENGTH_SHORT).show();
                    }
                }
            });
}

以下代码可以检查用户是否已登录

mAuthListener = new FirebaseAuth.AuthStateListener() {
            @Override
            public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) {
                final FirebaseUser user = firebaseAuth.getCurrentUser();
                if (user != null) {
                    // User is signed in
                    Log.d(TAG, "onAuthStateChanged:signed_in:" + user.getUid());

                    startActivity(new Intent(MainActivity.this,HomeActivity.class));
                } else {
                    // User is signed out
                    Log.d(TAG, "onAuthStateChanged:signed_out");
                }
            }
        };

我希望它有所帮助。如您所见FirebaseAuth往往帮助您在没有sharedPreference的情况下登录，但如果您想使用它，您可以确保在应用程序中单击SignOut按钮时销毁sharedPreference

Android - 用于经过身份验证的firebase用户的Alertdialog

2 个答案: