android - 实现 Google 登录，并变得奇怪 "unfortunately, MyApp has stopped"

Question

我在我的应用中实现了 Google 登录按钮。

一切都很好，除了一件事，当 Intent 提示用户选择一个 Google 帐户登录时，如果用户按下后退按钮，他将得到 unfortunately, MyApp has stopped 和该应用程序将崩溃。

我真的不知道应该从哪里开始为这个问题选择解决方案，我们将不胜感激。

她的是代码示例:

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) {

}

这是日志:

`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

在 onActivityResult 中试试这个

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

因为它可能没有登录并且返回空值。也对帐户进行空检查。

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