在Android Studio

Question

java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.Context android.content.Context.getApplicationContext()' on a null object reference

这是在MainActivity中：

 ContextWrapper bandContextWrapper = new ContextWrapper(getApplicationContext()) {
        @Override public boolean bindService(Intent service, ServiceConnection conn, int flags) {
            final String action = service.getAction();
            if (!TextUtils.isEmpty(action) && action.startsWith("com.microsoft.kapp")) {
                //service.setPackage("com.microsoft.band");
                service.setPackage("com.microsoft.kapp");
            }
            return super.bindService(service, conn, flags);
        }
    };

这是在Button的OnClickListener中：

bandClient = BandClientManager.getInstance().create(bandContextWrapper, pairedBands[0]);

这是初始化的地方：

私有View.OnClickListener btnSyncClickListener = new View.OnClickListener（）{

    @Override
    public void onClick(View button) {

        try {
            pairedBands = BandClientManager.getInstance().getPairedBands();
            bandClient = BandClientManager.getInstance().create(bandContextWrapper, pairedBands[0]);

          new ConnectTask().execute();
        }
        catch(Exception ex)
        {
            tvBandStatusMessage.setText("Could not connect");
        }
    }
};

按钮在OnCreate中初始化

protected void onCreate（Bundle savedInstanceState）{

    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);



    ImageView b = (ImageView)findViewById(R.id.btnSync);
    b.setOnClickListener(btnSyncClickListener);

}

启动模拟器时看到此错误。我正在使用Android Studio！