android eclipse如何使用意圖在默認導航抽屜中顯示第二個窗口

Question

因此，我是android編程新手，我也沒有java背景。

我的問題：是我的代碼可能嗎？

這是默認的導航抽屜項目代碼，我添加了代碼意圖，但是當我運行應用程序時，我得到「不幸的是，應用程序已停止」它是在開關情況下1.什麼即時嘗試要做的是當用戶點擊第1部分抽屜將顯示第1部分的窗口。

對不起新手在這裏。

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

當開始第二個活動時，您需要在您的意圖中使用該活動的類名稱。

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

我看不到您創建了NavigationDrawerFragment類。

這就是爲什麼它沒有響應。