即使用户在android studio中关闭应用程序，如何保持登录状态

Posted 2023-05-07

【中文标题】即使用户在android studio中关闭应用程序，如何保持登录状态

【英文标题】：How to remain signed in even when the user closes the app in android studio

【发布时间】：2021-09-06 02:42:08

【问题描述】：

一开始我在注销时遇到了问题 (link:How to logout a user when he wants to in android studio) 。我删除了即使在应用程序关闭后也有助于保持用户登录的部分，现在注销工作正常。但现在我的问题是我应该如何让用户保持登录状态？ 这是我的登录页面

public class Login_Page extends AppCompatActivity 
    ActivityLoginPageBinding binding;
    ProgressDialog progressdialog;
    FirebaseAuth auth;
    Button button;

    @Override
    protected void onCreate(Bundle savedInstanceState) 
        super.onCreate(savedInstanceState);
        binding = ActivityLoginPageBinding.inflate(getLayoutInflater());
        setContentView(binding.getRoot());
        button = findViewById(R.id.Googlelogin);
        button.setOnClickListener(new View.OnClickListener() 
            @Override
            public void onClick(View v) 
                Intent intent = new Intent(Login_Page.this, SignUp.class);
                startActivity(intent);
             //taking the user to signup page
        );
        auth = FirebaseAuth.getInstance();

            progressdialog = new ProgressDialog(Login_Page.this);
            progressdialog.setTitle("Logging in");
            progressdialog.setMessage("Please wait");
            binding.Login.setOnClickListener(new View.OnClickListener() 
                @Override
                public void onClick(View v) 
                    progressdialog.show();
                    auth.signInWithEmailAndPassword(binding.Email.getText().toString(), binding.Password.getText().toString())
                            .addOnCompleteListener(new OnCompleteListener<AuthResult>() 
                                @Override
                                public void onComplete(@NonNull Task<AuthResult> task) 
                                    progressdialog.dismiss();
                                    if (task.isSuccessful()) 
                                        Toast.makeText(Login_Page.this, "Success", Toast.LENGTH_SHORT).show();
                                        String uid = auth.getInstance().getCurrentUser().getUid();
                                        DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
                                        DatabaseReference uidRef = rootRef.child("Users").child("Driver").child(uid);
                                        ValueEventListener valueEventListener = new ValueEventListener() 
                                            @Override
                                            public void onDataChange(@NonNull DataSnapshot snapshot) 
                                                if (snapshot.exists()) 
                                                    Toast.makeText(Login_Page.this, "LoginDriver", Toast.LENGTH_SHORT);
                                                    Intent intent = new Intent(Login_Page.this, HomePage.class);
                                                    startActivity(intent);
                                                 else 
                                                    startActivity(new Intent(Login_Page.this, Custhomepage.class));
                                                
                                            

                                            @Override
                                            public void onCancelled(@NonNull DatabaseError error) 

                                            
                                        ;
                                        uidRef.addListenerForSingleValueEvent(valueEventListener);
                                     else 
                                        Toast.makeText(Login_Page.this, task.getException().getMessage(), Toast.LENGTH_SHORT);
                                    
                                
                            );

                
            );


        
    

【问题讨论】：

使用身份验证侦听器，就像我对这个post 的回答一样。

【参考方案1】：

我猜你没有检查用户是否登录。在activity的onCreate中，调用下面的方法checkFirebaseUser()

private void checkFirebaseUser () 
   FirebaseUser firebaseUser = mAuth.getCurrentUser ();
   if (firebaseUser != null) 
      //User is logged in already. You can proceed with your next screen
    else 
      //User not logged in. So show email and password edit text for user to enter credentials
  

希望上面的代码sn-p对你有帮助！

【讨论】：

嘿，我试过了，但是当我尝试注销时它开始产生问题

嘿@MohammadYusuf 看起来在注销时出现问题。我在上述链接中发布了针对您的问题的解决方案。希望对你有帮助