android eclipse如何使用intent在默认导航抽屉中显示第二个窗口

Question

所以我是新的Android编程中的新人，我也没有Java的背景。

我的问题：我的代码可行吗？

这是默认的导航抽屉项目代码，我添加了代码意图，但是当我运行应用程序时，我得到“不幸的是应用程序已停止”，它位于 switch case 1 上。我试图做的是当用户单击第 1 部分时将显示第 1 部分的窗口。

在这里对不起新手。

package com.example.example;

public class MainActivity extends Activity implements NavigationDrawerFragment.NavigationDrawerCallbacks {

    /**
     * Fragment managing the behaviors, interactions and presentation of the
     * navigation drawer.
     */
    private NavigationDrawerFragment mNavigationDrawerFragment;

    /**
     * Used to store the last screen title. For use in
     * {@link #restoreActionBar()}.
     */
    private CharSequence mTitle;

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

        mNavigationDrawerFragment = (NavigationDrawerFragment) getFragmentManager().findFragmentById(
                R.id.navigation_drawer);
        mTitle = getTitle();

        // Set up the drawer.
        mNavigationDrawerFragment.setUp(R.id.navigation_drawer, (DrawerLayout) findViewById(R.id.drawer_layout));
    }

    @Override
    public void onNavigationDrawerItemSelected(int position) {
        // update the main content by replacing fragments
        FragmentManager fragmentManager = getFragmentManager();
        fragmentManager.beginTransaction().replace(R.id.container, PlaceholderFragment.newInstance(position + 1))
                .commit();
    }

    public void onSectionAttached(int number) {
        switch (number) {
        case 1:
            mTitle = getString(R.string.title_section1);
            Intent intent = new Intent(MainActivity.this, NavigationDrawerFragment.class);
            startActivity(intent);
            break;
        case 2:
            mTitle = getString(R.string.title_section2);
            break;
        case 3:
            mTitle = getString(R.string.title_section3);
            break;
        }
    }

    public void restoreActionBar() {
        ActionBar actionBar = getActionBar();
        actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD);
        actionBar.setDisplayShowTitleEnabled(true);
        actionBar.setTitle(mTitle);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        if (!mNavigationDrawerFragment.isDrawerOpen()) {
            // Only show items in the action bar relevant to this screen
            // if the drawer is not showing. Otherwise, let the drawer
            // decide what to show in the action bar.
            getMenuInflater().inflate(R.menu.main, menu);
            restoreActionBar();
            return true;
        }
        return super.onCreateOptionsMenu(menu);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }

    /**
     * A placeholder fragment containing a simple view.
     */
    public static class PlaceholderFragment extends Fragment {
        /**
         * The fragment argument representing the section number for this
         * fragment.
         */
        private static final String ARG_SECTION_NUMBER = "section_number";

        /**
         * Returns a new instance of this fragment for the given section number.
         */
        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 PlaceholderFragment() {
        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.fragment_main, container, false);
            return rootView;
        }

        @Override
        public void onAttach(Activity activity) {
            super.onAttach(activity);
            ((MainActivity) activity).onSectionAttached(getArguments().getInt(ARG_SECTION_NUMBER));
        }
    }

}

Answer 1

开始第二个活动时，您需要在意图中使用该活动的类名。

Intent intent = new Intent(MainActivity.this, NavigationDrawerFragment.class);

我看不到你创建了一个NavigationDrawerFragment 类。

这就是它没有响应的原因。