我收到错误，找不到ID为0x7f09007c的视图

Question

我是Android开发的新手，正在尝试制作一个应用，但是一旦我打开我的应用，它就会显示上述错误 我在其他问题上尝试了前面提到的方法 这是我的主要活动

public class FreeCal extends AppCompatActivity {


    public ViewPager mViewPager;

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


        mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());

        mViewPager = findViewById(R.id.container);
        mViewPager.setAdapter(mSectionsPagerAdapter);

        TabLayout tabLayout = findViewById(R.id.tabs);

        mViewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
        tabLayout.addOnTabSelectedListener(new TabLayout.ViewPagerOnTabSelectedListener(mViewPager));
        mViewPager.setCurrentItem(1);

           }



        public PlaceholderFragment() {
        }
        public static PlaceholderFragment newInstance(int sectionNumber) {
            PlaceholderFragment fragment = new PlaceholderFragment();
            Bundle args = new Bundle();
            args.putInt(ARG_SECTION_NUMBER, sectionNumber);
            fragment.setArguments(args);
            return fragment;
        }

    }

    public class SectionsPagerAdapter extends FragmentPagerAdapter {

        public SectionsPagerAdapter(FragmentManager fm) {
            super(fm);
        }

        @Override
        public Fragment getItem(int position) {
           Fragment fragment = null;
           switch(position) {
               case 0:
                   fragment = new MenuFragment();
                   break;
               case 1:
                   fragment = new CalculatorFragment();
                   break;
               case 2:
                   fragment = new MoreFragment();
                   break;
               default:
                   fragment = new CalculatorFragment();
           }
           return fragment;

        }

        @Override
        public int getCount() {
            // Show 3 total pages.
            return 3;
        }
    }
}

**我认为这是我的片段，由于该片段而导致错误。我不知道该怎么办。由于此CalculatorFragment的onCreate方法而发生错误。我认为该错误与容器**

有关

public class CalculatorFragment extends Fragment implements View.OnClickListener {

    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
     View view = inflater.inflate(R.layout.fragment_calculator,container, false);
     return view;

**Here is my onCreateMethod for the fragment**

 public void onCreate(final Bundle bundle) {
        super.onCreate(bundle);
        final String string = PreferenceManager.getDefaultSharedPreferences(getActivity().getApplicationContext()).getString("theme", "0");
        switch ( string ) {
            case "0": {
                getActivity().setContentView(R.layout.fragment_calculator);
                break;
            }
            case "1": {
                getActivity().setContentView(R.layout.fragment_calculator_orange);
                break;
            }
        }
        this.z = getActivity().getSharedPreferences("calc_history", 0);
        this.A = getActivity().getSharedPreferences("calc_mode", 0);
        this.B = this.A.getBoolean("mode", false);
        if (this.B) {
            this.J = this.getString(R.string.screen_scientific);
        } else {
            this.J = this.getString(R.string.screen_standard);
        }
        this.l = getActivity().findViewById(R.id.txt_hint);
        this.m = getActivity().findViewById(R.id.txt_out);
        if (bundle != null) {
            this.r = bundle.getDouble("ans");
            this.s = bundle.getDouble("mreg");
            this.v = bundle.getString("current_token");
            this.n = bundle.getChar("lastkey");
            this.t = new LinkedList <String>(Arrays.asList(bundle.getStringArray("input_tokens")));
            this.m.setText(this.c(this.b(true)));
        }
        final Display defaultDisplay = getActivity().getWindowManager().getDefaultDisplay();
        final Point point = new Point();
        defaultDisplay.getSize(point);
        final int y = point.y;
        this.o = y / 9;
        if (this.B && this.getResources().getConfiguration().orientation == 1) {
            this.o = y / 12;

这是Logcat。我已经尝试了先前问题中提供的方法

java.lang.IllegalArgumentException: No view found for id 0x7f09007b (com.kingslayer.freecal_allinonecalculator:id/container) for fragment CalculatorFragment{e145b35 #0 id=0x7f09007b android:switcher:2131296379:1}
        at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1454)
        at 

Answer 1

检查您的setContentView(R.layout.activity_main);和班级名称FreeCal。

错误说找不到ID的视图。这意味着活动找不到布局文件。确保布局文件可用。