我在我的 android 应用程序中使用 Google plus 登录，它工作正常。

从任何其他 Intent 单击注销按钮时显示空指针异常。

同时点击登录按钮直接进入我的下一页。不是登录页面。

但是从演示应用程序注销它工作正常。

我已经搜索了相关的答案，没有找到任何解决方案仍然是一样的。

帮我解决一下

link 1

link 2

我已经引用了 2 个链接，但从下一个 Intent 注销时仍然显示空指针异常。

我的注销码:

public void googlePlusLogout() 
    {
        if (mGoogleApiClient.isConnected()) 
        {
            Plus.AccountApi.clearDefaultAccount(mGoogleApiClient);
            mGoogleApiClient.disconnect();
            mGoogleApiClient.connect();
            updateProfile(false);
        }

    }

这里是调用其他intent到signin类的方法

其他 Intent .java

                  session.logoutUser();// here i am clearing the shared pref
                  sign_in Signinclass = new sign_in();
                  Signinclass.googlePlusLogout();
                  finish(); 

这是我的演示代码，它工作正常 我在我的应用程序登录中使用的相同代码工作正常，但是从另一个页面调用的注销不起作用。显示空指针异常。

AndroidGooglePlusExample.java

public class AndroidGooglePlusExample extends Activity implements OnClickListener, ConnectionCallbacks, OnConnectionFailedListener {

    private static final int RC_SIGN_IN = 0;

    // Google client to communicate with Google
    private GoogleApiClient mGoogleApiClient;

    private boolean mIntentInProgress;
    private boolean signedInUser;
    private ConnectionResult mConnectionResult;
    private SignInButton signinButton;
    private ImageView image;
    private TextView username, emailLabel;
    private LinearLayout profileFrame, signinFrame;

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

        signinButton = (SignInButton) findViewById(R.id.signin);
        signinButton.setOnClickListener(this);

        image = (ImageView) findViewById(R.id.image);
        username = (TextView) findViewById(R.id.username);
        emailLabel = (TextView) findViewById(R.id.email);

        profileFrame = (LinearLayout) findViewById(R.id.profileFrame);
        signinFrame = (LinearLayout) findViewById(R.id.signinFrame);

        mGoogleApiClient = new GoogleApiClient.Builder(this).addConnectionCallbacks(this).addOnConnectionFailedListener(this).addApi(Plus.API, Plus.PlusOptions.builder().build()).addScope(Plus.SCOPE_PLUS_LOGIN).build();
    }

    protected void onStart() {
        super.onStart();
        mGoogleApiClient.connect();
    }

    protected void onStop() {
        super.onStop();
        if (mGoogleApiClient.isConnected()) {
            mGoogleApiClient.disconnect();
        }
    }

    private void resolveSignInError() {
        if (mConnectionResult.hasResolution()) {
            try {
                mIntentInProgress = true;
                mConnectionResult.startResolutionForResult(this, RC_SIGN_IN);
            } catch (SendIntentException e) {
                mIntentInProgress = false;
                mGoogleApiClient.connect();
            }
        }
    }

    @Override
    public void onConnectionFailed(ConnectionResult result) {
        if (!result.hasResolution()) {
            GooglePlayServicesUtil.getErrorDialog(result.getErrorCode(), this, 0).show();
            return;
        }

        if (!mIntentInProgress) {
            // store mConnectionResult
            mConnectionResult = result;

            if (signedInUser) {
                resolveSignInError();
            }
        }
    }

    @Override
    protected void onActivityResult(int requestCode, int responseCode, Intent intent) {
        switch (requestCode) {
        case RC_SIGN_IN:
            if (responseCode == RESULT_OK) {
                signedInUser = false;

            }
            mIntentInProgress = false;
            if (!mGoogleApiClient.isConnecting()) {
                mGoogleApiClient.connect();
            }
            break;
        }
    }

    @Override
    public void onConnected(Bundle arg0) {
        signedInUser = false;
        Toast.makeText(this, "Connected", Toast.LENGTH_LONG).show();
        getProfileInformation();
    }

    private void updateProfile(boolean isSignedIn) {
        if (isSignedIn) {
            signinFrame.setVisibility(View.GONE);
            profileFrame.setVisibility(View.VISIBLE);

        } else {
            signinFrame.setVisibility(View.VISIBLE);
            profileFrame.setVisibility(View.GONE);
        }
    }

    private void getProfileInformation() {
        try {
            if (Plus.PeopleApi.getCurrentPerson(mGoogleApiClient) != null) {
                Person currentPerson = Plus.PeopleApi.getCurrentPerson(mGoogleApiClient);
                String personName = currentPerson.getDisplayName();
                String personPhotoUrl = currentPerson.getImage().getUrl();
                String email = Plus.AccountApi.getAccountName(mGoogleApiClient);

                username.setText(personName);
                emailLabel.setText(email);

                new LoadProfileImage(image).execute(personPhotoUrl);

                // update profile frame with new info about Google Account
                // profile
                updateProfile(true);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    @Override
    public void onConnectionSuspended(int cause) {
        mGoogleApiClient.connect();
        updateProfile(false);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
        case R.id.signin:
            googlePlusLogin();
            break;
        }
    }

    public void signIn(View v) {
        googlePlusLogin();
    }

    public void logout(View v) {
        googlePlusLogout();
    }

    private void googlePlusLogin() {
        if (!mGoogleApiClient.isConnecting()) {
            signedInUser = true;
            resolveSignInError();
        }
    }

    private void googlePlusLogout() {
        if (mGoogleApiClient.isConnected()) {
            Plus.AccountApi.clearDefaultAccount(mGoogleApiClient);
            mGoogleApiClient.disconnect();
            mGoogleApiClient.connect();
            updateProfile(false);
        }
    }

    // download Google Account profile image, to complete profile
    private class LoadProfileImage extends AsyncTask<String, Void, Bitmap> {
        ImageView downloadedImage;

        public LoadProfileImage(ImageView image) {
            this.downloadedImage = image;
        }

        protected Bitmap doInBackground(String... urls) {
            String url = urls[0];
            Bitmap icon = null;
            try {
                InputStream in = new java.net.URL(url).openStream();
                icon = BitmapFactory.decodeStream(in);
            } catch (Exception e) {
                Log.e("Error", e.getMessage());
                e.printStackTrace();
            }
            return icon;
        }

        protected void onPostExecute(Bitmap result) {
            downloadedImage.setImageBitmap(result);
        }
    }

最佳答案

我找到了我的问题的解决方案

将此代码添加到您的注销 Activity 页面中。效果很好

我的注销页面 Activity

 public class LogoutActivity extends Activity implements OnClickListener,
        ConnectionCallbacks, OnConnectionFailedListener,
        ResultCallback<People.LoadPeopleResult> {

       GoogleApiClient mGoogleApiClient;
       boolean mSignInClicked;

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

        mGoogleApiClient = new GoogleApiClient.Builder(this)
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this).addApi(Plus.API)
                .addScope(Plus.SCOPE_PLUS_LOGIN).build();

         //copy this code on "Logout" Onclick
      logout.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                 if (mGoogleApiClient.isConnected()) {
                Plus.AccountApi.clearDefaultAccount(mGoogleApiClient);
                mGoogleApiClient.disconnect();
                mGoogleApiClient.connect();
                // updateUI(false);
                System.err.println("LOG OUT ^^^^^^^^^^^^^^^^^^^^ SUCESS");
            } 

            }
        });

    }
    @Override
    public void onConnected(Bundle arg0) {
        // TODO Auto-generated method stub
        mSignInClicked = false;

        // updateUI(true);
        Plus.PeopleApi.loadVisible(mGoogleApiClient, null).setResultCallback(
                this);
    }

    @Override
    public void onConnectionSuspended(int arg0) {
        // TODO Auto-generated method stub
        mGoogleApiClient.connect();
        // updateUI(false);
    }

    @Override
    public void onConnectionFailed(ConnectionResult arg0) {
        // TODO Auto-generated method stub

    }

    protected void onStart() {
        super.onStart();
        mGoogleApiClient.connect();
    }

    protected void onStop() {
        super.onStop();
        if (mGoogleApiClient.isConnected()) {
            mGoogleApiClient.disconnect();
        }
    }

    @Override
    public void onResult(LoadPeopleResult arg0) {
        // TODO Auto-generated method stub

    }

link for reference

关于android - 从 Google plus 帐户注销在 android 中不工作，显示空指针异常，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/30731498/