Android 用户登录后如何将LoginActivity从SplashScreenActivity重定向到MainActivity

我试了很多次，但每次我都在运行我的应用。。启动屏幕后，即使用户已经通过google帐户登录，google登录活动也会打开。一旦用户登录，我想跳过登录活动

任何 如有建议，将不胜感激。请您用适当的代码回答

以下是我的SplashScreen代码：

这是我的登录码：

---

您只需在用户已登录时签入您的SplashActivity，即可实现此目的：

  GoogleSignInAccount account = GoogleSignIn.getLastSignedInAccount(this);
  if(account != null){ 
    // user is logged in
     Intent intent = new Intent(SplashActivity.this, MainActivity.class);
    intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK);
    startActivity(intent);
}
 else {
//user is not logged in
  Intent intent = new Intent(SplashActivity.this, LoginActivity.class);
    intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK);
    startActivity(intent);
}

---

将此代码放入onStart函数并检查是否已登录

发布代码请在第一次访问所有数据时使用SharedPerference或Sqlite数据库创建会话。是否使用Firebase登录？在developer.android.com上阅读有关SharedReferences的信息，您将找到解决方案并始终尝试搜索询问问题前的Stackoverflow我正在使用google登录

 public class LoginActivity extends AppCompatActivity {

//a constant for detecting the login intent result
private static final int RC_SIGN_IN = 234;

//Tag for the logs optional
private static final String TAG = "AMOLEDify";

//creating a GoogleSignInClient object
GoogleSignInClient mGoogleSignInClient;

//And also a Firebase Auth object
FirebaseAuth mAuth;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.login_page);

    //first we intialized the FirebaseAuth object
    mAuth = FirebaseAuth.getInstance();

    //Then we need a GoogleSignInOptions object
    //And we need to build it as below
    GoogleSignInOptions gso = new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
            .requestIdToken(getString(R.string.default_web_client_id))
            .requestEmail()
            .build();

    //Then we will get the GoogleSignInClient object from GoogleSignIn class
    mGoogleSignInClient = GoogleSignIn.getClient(this, gso);

    //Now we will attach a click listener to the sign_in_button
    //and inside onClick() method we are calling the signIn() method that will open
    //google sign in intent
    findViewById(R.id.sign_in_button).setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            signIn();
        }
    });
}

@Override
protected void onStart() {
    super.onStart();

    if (mAuth.getCurrentUser() != null) {
        finish();
        startActivity(new Intent(this, SignInProfile.class));
    }

}

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

    //if the requestCode is the Google Sign In code that we defined at starting
    if (requestCode == RC_SIGN_IN) {

        //Getting the GoogleSignIn Task
        Task<GoogleSignInAccount> task = GoogleSignIn.getSignedInAccountFromIntent(data);
        try {
            //Google Sign In was successful, authenticate with Firebase
            GoogleSignInAccount account = task.getResult(ApiException.class);

            //authenticating with firebase
            firebaseAuthWithGoogle(account);
        } catch (ApiException e) {
            Toast.makeText(LoginActivity.this, e.getMessage(), Toast.LENGTH_SHORT).show();
        }
    }
}

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

    //getting the auth credential
    AuthCredential credential = GoogleAuthProvider.getCredential(acct.getIdToken(), null);

    //Now using firebase we are signing in the user here
    mAuth.signInWithCredential(credential)
            .addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
                @Override
                public void onComplete(@NonNull Task<AuthResult> task) {
                    if (task.isSuccessful()) {
                        Log.d(TAG, "signInWithCredential:success");
                        FirebaseUser user = mAuth.getCurrentUser();

                        Toast.makeText(LoginActivity.this, "User Signed In", Toast.LENGTH_SHORT).show();


                    } else {
                        // If sign in fails, display a message to the user.
                        Log.w(TAG, "signInWithCredential:failure", task.getException());
                        Toast.makeText(LoginActivity.this, "Authentication failed.",
                                Toast.LENGTH_SHORT).show();

                    }

                }
            });
}

//this method is called on click
private void signIn() {
    //getting the google signin intent
    Intent signInIntent = mGoogleSignInClient.getSignInIntent();

    //starting the activity for result
    startActivityForResult(signInIntent, RC_SIGN_IN);
}
}

  GoogleSignInAccount account = GoogleSignIn.getLastSignedInAccount(this);
  if(account != null){ 
    // user is logged in
     Intent intent = new Intent(SplashActivity.this, MainActivity.class);
    intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK);
    startActivity(intent);
}
 else {
//user is not logged in
  Intent intent = new Intent(SplashActivity.this, LoginActivity.class);
    intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK);
    startActivity(intent);
}

    OptionalPendingResult<GoogleSignInResult> opr = Auth.GoogleSignInApi.silentSignIn(mGoogleApiClient);
    if (opr.isDone()) {
        Log.d("Already signed in", "Got cached sign-in");
        GoogleSignInResult result = opr.get();
        startActivity(new Intent(this, SignInProfile.class));
        //result(result);
    } else {
        opr.setResultCallback(new ResultCallback<GoogleSignInResult>() {
            @Override
            public void onResult(GoogleSignInResult googleSignInResult) {

                //result(googleSignInResult);
            }
        });
    }