Googleでサインインを実装していて不幸にも「残念なことにMyAppが停止しました」

Question

私のアプリにGoogle Sign-Inボタンを実装しました。

すべてはユーザーのプレス戻るボタンならば、彼はunfortunately, MyApp has stoppedを取得すると、アプリがクラッシュします、意図がでログインするGoogleアカウントを選択を促す際に、一つのことを除いて、本当によく働きます。

私はこの問題の解決方法をどこから選ぶべきかは分かりません。

ハーズは、コードのサンプルです：

private SignInButton googleLogin; 
private GoogleApiClient apiClient; 
private GoogleSignInOptions gso; 
private String googleUserName; 
private String googleUserMail; 
private static final int REQ_ID = 9001; 

gso = new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN) 
      .requestEmail() 
      .build(); 
    apiClient = new GoogleApiClient.Builder(this) 
      .enableAutoManage(this,this) 
      .addApi(Auth.GOOGLE_SIGN_IN_API, gso) 
      .build(); 

    googleLogin = (SignInButton) findViewById(R.id.googleSignIn); 
    googleLogin.setSize(SignInButton.SIZE_STANDARD); 
    googleLogin.setScopes(gso.getScopeArray()); 

googleLogin.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       Intent signIntent = Auth.GoogleSignInApi.getSignInIntent(apiClient); 
       startActivityForResult(signIntent,REQ_ID); 
      } 
     }); 

@Override 
protected void onActivityResult(final int requestCode, final int resultCode, final Intent data) { 
    super.onActivityResult(requestCode, resultCode, data); 
    callbackManager.onActivityResult(requestCode, resultCode, data); 
    if(requestCode == REQ_ID) 
    { 
     GoogleSignInResult res = Auth.GoogleSignInApi.getSignInResultFromIntent(data); 
     GoogleSignInAccount account = res.getSignInAccount(); 
     googleUserName = account.getDisplayName().toString(); 
     googleUserMail = account.getEmail().toString(); 


    } 
} 
@Override 
public void onConnectionFailed(ConnectionResult connectionResult) { 

} 

そして、ここでは、ログです：そのおそらくサインインしていないので

`05-27 06:06:56.420 22660-22738/com.MyApp W/EGL_emulation: eglSurfaceAttrib not implemented 
05-27 06:06:56.420 22660-22738/com.MyApp W/OpenGLRenderer: Failed to set EGL_SWAP_BEHAVIOR on surface 0x99ada7c0, error=EGL_SUCCESS 
05-27 06:07:03.147 22660-22660/com.MyApp D/AndroidRuntime: Shutting down VM 
05-27 06:07:03.147 22660-22660/com.MyApp E/AndroidRuntime: FATAL EXCEPTION: main 
                     Process: com.MyApp, PID: 22660 
                     java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=9001, result=0, data=Intent { (has extras) }} to activity {com.MyApp/com.MyApp.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String com.google.android.gms.auth.api.signin.GoogleSignInAccount.getDisplayName()' on a null object reference 
                      at android.app.ActivityThread.deliverResults(ActivityThread.java:3699) 
                      at android.app.ActivityThread.handleSendResult(ActivityThread.java:3742) 
                      at android.app.ActivityThread.-wrap16(ActivityThread.java) 
                      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1393) 
                      at android.os.Handler.dispatchMessage(Handler.java:102) 
                      at android.os.Looper.loop(Looper.java:148) 
                      at android.app.ActivityThread.main(ActivityThread.java:5417) 
                      at java.lang.reflect.Method.invoke(Native Method) 
                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) 
                     Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String com.google.android.gms.auth.api.signin.GoogleSignInAccount.getDisplayName()' on a null object reference 
                      at com.door.global.store.MainActivity.onActivityResult(MainActivity.java:200) 
                      at android.app.Activity.dispatchActivityResult(Activity.java:6428) 
                      at android.app.ActivityThread.deliverResults(ActivityThread.java:3695) 
                      at android.app.ActivityThread.handleSendResult(ActivityThread.java:3742)  
                      at android.app.ActivityThread.-wrap16(ActivityThread.java)  
                      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1393)  
                      at android.os.Handler.dispatchMessage(Handler.java:102)  
                      at android.os.Looper.loop(Looper.java:148)  
                      at android.app.ActivityThread.main(ActivityThread.java:5417)  
                      at java.lang.reflect.Method.invoke(Native Method)  
                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)  
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)  
` 

Answer 1

はonActivityResult

if(requestCode == REQ_ID && resultCode == Activity.RESULT_OK). 

でこれを試してみて、戻り値null。アカウントについてもヌルチェックを行います。

GoogleSignInAccount account = res.getSignInAccount(); 
if(account != null){ 
     googleUserName = account.getDisplayName().toString(); 
     googleUserMail = account.getEmail().toString(); 
}