Question

我尝试了谷歌开发者文档，并尝试登录我的应用程序。代码是从git复制的，其中添加了documentation.的代码并在 LoginActivity 中定义为

Public class LoginActivity extends AppCompatActivity implements
    GoogleApiClient.OnConnectionFailedListener,
    View.OnClickListener {

private static final String TAG = "* * SignIn * *";
private static final int RC_SIGN_IN = 9001;

private GoogleApiClient mGoogleApiClient;
private ProgressDialog mProgressDialog;
Bundle userData = new Bundle();
Intent newIntent;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.login);
   findViewById(R.id.sign_in_button).setOnClickListener(this);


    // [START configure_signin]
    // Configure sign-in to request the user's ID, email address, and basic
    // profile. ID and basic profile are included in DEFAULT_SIGN_IN.
    GoogleSignInOptions gso = new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
            .requestEmail()
            .build();
    // [END configure_signin]

    // [START build_client]
    mGoogleApiClient = new GoogleApiClient.Builder(this)
            .enableAutoManage(this /* FragmentActivity */, this /* OnConnectionFailedListener */)
            .addApi(Auth.GOOGLE_SIGN_IN_API, gso)
            .build();
    // [END build_client]

    // [START customize_button]
    SignInButton signInButton = (SignInButton) findViewById(R.id.sign_in_button);
    signInButton.setSize(SignInButton.SIZE_STANDARD);
    signInButton.setScopes(gso.getScopeArray());
    // [END customize_button]
}

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

    OptionalPendingResult<GoogleSignInResult> opr = Auth.GoogleSignInApi.silentSignIn(mGoogleApiClient);
    if (opr.isDone()) {
        Log.d(TAG, "Got cached sign-in");
        GoogleSignInResult result = opr.get();
        handleSignInResult(result);
    } else {

        showProgressDialog();
        opr.setResultCallback(new ResultCallback<GoogleSignInResult>() {
            @Override
            public void onResult(GoogleSignInResult googleSignInResult) {
                hideProgressDialog();
                handleSignInResult(googleSignInResult);
            }
        });
    }
}

// [START onActivityResult]
@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);
        handleSignInResult(result);
    }
}
// [END onActivityResult]

// [START handleSignInResult]
private void handleSignInResult(GoogleSignInResult result) {
    Log.d(TAG, "handleSignInResult:" + result.isSuccess());
    if (result.isSuccess()) {
        // Signed in successfully, show authenticated UI.
        GoogleSignInAccount acct = result.getSignInAccount();
        userData.putString("Username", acct.getDisplayName());
        userData.putString("Email",acct.getEmail());
        newIntent = new Intent(LoginActivity.this, MainActivity.class);
        newIntent.putExtras(userData);
        startActivity(newIntent);
        finish();
    } else {
        userData.putString("Username", "Anonymous");
        userData.putString("Email","www.example.com");
        newIntent = new Intent(LoginActivity.this, MainActivity.class);
        newIntent.putExtras(userData);
        startActivity(newIntent);
        finish();
    }
}
// [END handleSignInResult]

// [START signIn]
private void signIn() {
    Intent signInIntent = Auth.GoogleSignInApi.getSignInIntent(mGoogleApiClient);
    startActivityForResult(signInIntent, RC_SIGN_IN);
}
// [END signIn]





@Override
public void onConnectionFailed(ConnectionResult connectionResult) {
            Log.d(TAG, "onConnectionFailed:" + connectionResult);
}

private void showProgressDialog() {
    if (mProgressDialog == null) {
        mProgressDialog = new ProgressDialog(this);
        mProgressDialog.setMessage("Please wait");
        mProgressDialog.setIndeterminate(true);
    }

    mProgressDialog.show();
}

private void hideProgressDialog() {
    if (mProgressDialog != null && mProgressDialog.isShowing()) {
        mProgressDialog.hide();
    }
}
@Override
public void onClick(View v) {
    switch (v.getId()) {
        case R.id.sign_in_button:
            signIn();
            break;

    }
}

}

但我收到以下错误log. 如

12-16 23:02:44.074 5545-5545/com.example.www.newapp E/AndroidRuntime: java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=40962, result=-1, data=Intent { (has extras) }} 
                                                                     to activity {com.example.www.newapp/com.google.android.gms.auth.api.signin.internal.SignInHubActivity}: 
                                                                    java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.Class java.lang.Object.getClass()' on a null object reference

我的 MainActivity 代码为

public class MainActivity extends AppCompatActivity
    implements NavigationView.OnNavigationItemSelectedListener, View.OnClickListener {
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
    View header = navigationView.getHeaderView(0);
    userName = (TextView) header.findViewById(R.id.userName);
    userName.setText(user);//Username recieved through intent
}}

在模拟器中运行它会显示更新您的播放服务，这是一个问题吗？

Answer 1

在使用新的播放服务8.3进行编译时，仅在模拟器中出现错误虽然在实际硬件中进行测试并未显示任何问题。这是由于模拟器和API中的播放服务版本不匹配。希望他们使用最新的播放服务升级Google API SDK并发布一些关于它的通知。

Answer 2

当您调用signIn()方法时，方法无法找到startActivityForResult。哪里有错误。

您需要@override startActivityForResult代表LoginActivity。在LoginActivity添加以下代码。

<强>代码：

 @Override
public void startActivityForResult(Intent intent, int requestCode) {
    super.startActivityForResult(intent, requestCode);
}

适用于Android的Google SIgn-In

2 个答案: