Question

我正在用我的android应用片段集成Google登录。但是当我登录它时，打开一个新的片段b。但是当片段b当我按位置登录按钮时，它再次显示登录窗口

我已经使用fragmentTransaction.addToBackStack（null）;

登录片段（片段a）

public class LoginFragment1 extends Fragment {
 int RC_SIGN_IN = 9001;
GoogleSignInClient mGoogleSignInClient;
SignInButton signInButton;
LoginButton loginButton;
LinearLayout linearLayout,linearLayout1;
CallbackManager callbackManager;
private static final String EMAIL = "email";

@Override
public void onStart() {
    super.onStart();
    GoogleSignInAccount account = 
    GoogleSignIn.getLastSignedInAccount(getActivity());
  if(account!=null){
updateUI(account);

     }
}

@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

      callbackManager = CallbackManager.Factory.create();

    LoginManager.getInstance().registerCallback(callbackManager, new 
     FacebookCallback<LoginResult>() {
        @Override
        public void onSuccess(LoginResult loginResult) {
            Log.d(TAG, "onSuccess: "+loginResult );
        }

        @Override
        public void onCancel() {
            Log.d(TAG, "onCancel: ");
        }

        @Override
        public void onError(FacebookException error) {
            Log.e(TAG, "onError: ",error );
        }
    });
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    GoogleSignInOptions gso = new 
     GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
            .requestEmail()
            .build();
    View view =  inflater.inflate(R.layout.fragment_login_fragment1, 
    container, false);
    //seting apps name
    TextView textView = view.findViewById(R.id.textView6);
    String text = "Lets<font color='#faa71a'>Go</font>";

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {

        textView.setText(Html.fromHtml(text,  Html.FROM_HTML_MODE_LEGACY), 
    TextView.BufferType.SPANNABLE);

    } else {
        textView.setText(Html.fromHtml(text), 
    TextView.BufferType.SPANNABLE);
    }



    //google login
     linearLayout = view.findViewById(R.id.linearLayout);
    signInButton = view.findViewById(R.id.signInButton);
    linearLayout.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            signInButton.performClick();
            signIn();
        }
    });
     mGoogleSignInClient = GoogleSignIn.getClient(getActivity(), gso);
    //facebook login
    linearLayout1 = view.findViewById(R.id.linearLayout2);
    loginButton = view.findViewById(R.id.loginButton);
    CallbackManager callbackManager = CallbackManager.Factory.create();
    linearLayout1.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            loginButton.performClick();

        }
    });

    loginButton.setFragment(this);
    loginButton.setReadPermissions(Arrays.asList("email", "public_profile", "user_friends"));


    return view;
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {

    // Result returned from launching the Intent from GoogleSignInClient.getSignInIntent(...);
    if (requestCode == RC_SIGN_IN) {
        // The Task returned from this call is always completed, no need to attach
        // a listener.
        Task<GoogleSignInAccount> task = GoogleSignIn.getSignedInAccountFromIntent(data);
        handleSignInResult(task);
    }
    callbackManager.onActivityResult(requestCode, resultCode, data);
    super.onActivityResult(requestCode, resultCode, data);

}
private void handleSignInResult(Task<GoogleSignInAccount> completedTask) {
    try {
        GoogleSignInAccount account = completedTask.getResult(ApiException.class);

        // Signed in successfully, show authenticated UI.
        updateUI(account);
    } catch (ApiException e) {
        // The ApiException status code indicates the detailed failure reason.
        // Please refer to the GoogleSignInStatusCodes class reference for more information.
        Log.w(TAG, "signInResult:failed code=" + e.getStatusCode());
        updateUI(null);
    }

}
private void signIn() {
    Intent signInIntent = mGoogleSignInClient.getSignInIntent();
    startActivityForResult(signInIntent, RC_SIGN_IN);
}

private void updateUI(GoogleSignInAccount account) {
    Toast.makeText(getActivity(),"signedin" ,Toast.LENGTH_SHORT).show();
    Fragment fragment = new StepFragment();
    FragmentManager fragmentManager = getFragmentManager();
    FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
    fragmentTransaction.replace(R.id.fragment, fragment);
    fragmentTransaction.addToBackStack(null);
    fragmentTransaction.commit();


  Toast.makeText(getActivity(),
  account.getDisplayName()+"\n"+account.getEmail(),
 Toast.LENGTH_SHORT).show();
  }

}

用户片段（片段b）

 public class StepFragment extends Fragment {
Button Logoutl;
GoogleSignInClient mGoogleSignInClient;
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    View view = inflater.inflate(R.layout.fragment_step, container, false);

    GoogleSignInOptions gso = new 
 GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
            .requestEmail()
            .build();
    mGoogleSignInClient = (GoogleSignInClient) GoogleSignIn.getClient(getActivity(), gso);
    Logoutl = view.findViewById(R.id.button2);
    Logoutl.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            mGoogleSignInClient.signOut();
        }
    });
    Fragment fragment = new LoginFragment1();
    FragmentManager fragmentManager = getFragmentManager();

    FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
    fragmentTransaction.detach(fragment);
    fragmentTransaction.commit();
    return view;
}

}

Answer 1

在内部登录片段中为登录片段创建TAG名称，例如public static String TAG = "Login";

在Second Fragment内创建一个函数，如下所示

public void removeFragmentByTag(String tag) {
    Fragment fragment = getSupportFragmentManager().findFragmentByTag(tag);
    if (fragment != null) {
        getSupportFragmentManager().beginTransaction().remove(fragment).commit();
    }
}

在“第二个片段”中，通过传递登录片段TAG名称（例如）来调用此方法

removeFragmentByTag(Login.TAG);

它将删除登录片段

Answer 2

另一种方法是使用Otto之类的库在事件总线上发送事件。由于片段的固有性质，使用add方法添加的所有彼此重叠的片段都是活动的，不会暂停。...因此，您触发的任何事件都会传递所有活动的侦听器。

创建一个事件类

public class CloseFrag{}

在需要的片段中声明事件总线

private static final Bus eventBus = new Bus(ThreadEnforcer.ANY);

在需要的片段的onResume中注册事件总线：

@Override
public void onResume() {

    eventBus.register(this);

    super.onResume();
}

在需要的片段的onPause中取消注册事件总线

@Override
public void onPause() {

    eventBus.unregister(this);

    super.onPause();
}

存在Google登录信息的片段中，一旦登录完成便触发该事件

eventBus.post(new CloseFrag());

在要关闭的片段中，注册总线后收听事件

@Subscribe
public void event(CloseFrag event){

   //Take necessary action eg popBackStack() or getActivity().finish() as per your need

}

如何在片段b上关闭片段a？

2 个答案: