小编ajz*_*ija的帖子

我正在尝试实现 Facebook 登录按钮，但在尝试运行应用程序时收到这些错误：

错误：

FATAL EXCEPTION: AsyncTask #4
Process: , PID: 4633
java.lang.NullPointerException: Attempt to invoke virtual method 'int java.lang.Object.hashCode()' on a null object reference
    at java.util.concurrent.ConcurrentHashMap.get(ConcurrentHashMap.java:746)
    at java.util.concurrent.ConcurrentHashMap.containsKey(ConcurrentHashMap.java:774)
    at com.facebook.internal.Utility.queryAppSettings(Utility.java:825)
    at com.facebook.login.widget.LoginButton$1.run(LoginButton.java:489)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
    at java.lang.Thread.run(Thread.java:818)
com.android.vlada.sportisa E/GoogleApiAvailability: Google Play services is invalid. Cannot recover.

代码：

public class MainActivity extends AppCompatActivity implements GoogleApiClient.OnConnectionFailedListener {

    private Button buttonRegistrujSe, buttonPrijaviSeKaoGost, buttonPrijavaRegistrovaniKorisnik;
    private LoginButton loginButton;
    private CallbackManager callbackManager;
    private TextView info;

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

我没有带下划线的代码,但只要我在模拟器上启动我的应用程序,我就会收到这些错误.

    FATAL EXCEPTION: main
Process: com.milos.sportisa, PID: 2735
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.milos.sportisa/com.milos.sportisa.SplashActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setTypeface(android.graphics.Typeface)' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2298)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
at android.app.ActivityThread.access$800(ActivityThread.java:144)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5221)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setTypeface(android.graphics.Typeface)' on a null object reference
at com.milos.sportisa.SplashActivity.onCreate(SplashActivity.java:29)
at android.app.Activity.performCreate(Activity.java:5933)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360) 
at android.app.ActivityThread.access$800(ActivityThread.java:144) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278) 
at …