空对象引用(android Lint)上的android.view.view.findViewById(int)

我有个问题。我在安卓工作室运行Lint，它修复了我的应用程序的一些部分，但之后这个应用程序无法启动。它写道：

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.cewe.martin.cewetracking/com.cewe.martin.cewetracking.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.View android.view.View.findViewById(int)' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2778)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2856)
at android.app.ActivityThread.-wrap11(Unknown Source:0)

我找不到，问题出在哪里。我无法撤消，因为有一些更改的文件，所以我试图删除对我来说不常见的部分，但它仍然无法启动。以下是MainActivity的创建方法：

public class MainActivity extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener {
private DrawerLayout drawer;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
drawer = findViewById(R.id.drawer_layout);
NavigationView navigationView = findViewById(R.id.nav_view);
navigationView.setNavigationItemSelectedListener(this);
ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
drawer.addDrawerListener(toggle);
toggle.syncState();
if (savedInstanceState == null) {
Log.d("START","DO IFU");
getSupportFragmentManager().beginTransaction().replace(R.id.fragment_container, new ScanFragment()).commit();
Log.d("START","ZA GETSUPP");
navigationView.setCheckedItem(R.id.nav_scan);
}
}

你可以看到Log.d。第一个"DO IFU"显示，第二个没有，所以我认为，它可能在ScanFragment((中。此处编码：

public class ScanFragment extends Fragment {
private final EditText rucneKod = (EditText) getView().findViewById(R.id.numberInput);
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
final View view = inflater.inflate(R.layout.fragment_scan, container, false);
Button skenovaciTlacitko = view.findViewById(R.id.button2);
skenovaciTlacitko.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
zapnoutSkener();
}
});
Button rucne = view.findViewById(R.id.button3);
View.OnFocusChangeListener ofcListener = new MyFocusChangeListener();
rucneKod.setOnFocusChangeListener(ofcListener);
final InputMethodManager imm = (InputMethodManager) getActivity().getSystemService(Context.INPUT_METHOD_SERVICE);
rucne.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (rucneKod.getText().length() != 0) {
imm.hideSoftInputFromWindow(v.getWindowToken(), 0);
odeslat(rucneKod.getText().toString());
} else {
imm.hideSoftInputFromWindow(v.getWindowToken(), 0);
Snackbar snackbar = Snackbar.make(view, R.string.pozadovanKod, Snackbar.LENGTH_LONG);
View sbView = snackbar.getView();
TextView textView = sbView.findViewById(android.support.design.R.id.snackbar_text);
textView.setTextColor(Color.YELLOW);
snackbar.show();
}
}
});
return view;
}

有人能看到有问题的代码吗？感谢