從基本活動中獲取片段內容

Question

我的應用程序總是使用相同的菜單，所以我定義了一個BaseActivity，並且每個活動現在都擴展了BaseActivity。

的東西是菜單的一個元素被用於同步系統。所以，根據我在活動中，它應該刷新不同的元素：列表視圖，地圖等..

我能知道哪些活動是使用上onStartMethod SharedPreference頂部。

但是從我BaseActivity，我無法檢索它們內部子活動和片段。

我：

public class FragmentTabsPdv extends BaseActivity 

裏面FragmentTabsPdv，我有一個福爾摩斯標籤，用2片段：

ListPdvTabFragment extends SherlockFragment 
MapPdvTabFragment extends SherlockFragment 

裏面ListPdvTabFragment，我想刷新我的ListView，但我不知道如何從BaseActivity獲得它。

當然，我的菜單是定義BaseActivity：

的同步菜單啓動的AsyncTask誰從服務器獲取新內容和更新sqlite的分貝。 和過程onPostExecute結束，我需要更新我的元素：

@Override 
protected void onPostExecute(Void result) { 
    super.onPostExecute(result); 
    if (lTiendas == null){ 
     Toast.makeText(ctx, "Hubo un error al sincronizar los datos, intentalo más tarde", Toast.LENGTH_LONG).show(); 
    } 

    if (BaseActivity.refreshItem != null) { 
     String frontActivity = prefs.getString("FrontActivity", ""); 
     if (!frontActivity.isEmpty()){ 
      if (frontActivity.equals("ListPdvTabFragment")){ 
       // get List to Refresh 
      } 
     } 


     BaseActivity.completeRefresh(); 
    } else { 

     Intent i = new Intent(ctx, DashBoard.class); 
     i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK); 
     ctx.startActivity(i); 

     if ((SplashScreen) ctx != null) 
      ((SplashScreen) ctx).finish(); 
    } 

} 

選項卡活動：

public class FragmentTabsPdv extends BaseActivity { 
private ArrayList<Pdv> listaPdv; 
private Usuario mUser; 
private SharedPreferences prefs; 
private Context ctx; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    ctx = this; 
    getSupportActionBar().setDisplayHomeAsUpEnabled(true); 
    prefs = PreferenceManager.getDefaultSharedPreferences(this); 

    DatabaseHandlerTienda db = new DatabaseHandlerTienda(this); 
    // listaPdv = (ArrayList<Pdv>) db.getAllTiendas(); 
    String jsonUser = prefs.getString("usuario", ""); 
    Gson gson = new Gson(); 
    mUser = gson.fromJson(jsonUser, Usuario.class); 
    listaPdv = db.getAllTiendas(); 

    ActionBar actionBar = getSupportActionBar(); 
    actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS); 
    ActionBar.Tab tab1 = actionBar.newTab(); 
    tab1.setText("Lista"); 
    tab1.setIcon(R.drawable.ic_action_view_as_list); 

    ActionBar.Tab tab2 = getSupportActionBar().newTab(); 
    tab2.setText("Mapa"); 
    tab2.setIcon(R.drawable.ic_action_location_map); 

    // create the two fragments we want to use for display content 

    tab1.setTabListener(new TabListener<ListPdvTabFragment>(this, "lista", ListPdvTabFragment.class)); 
    tab2.setTabListener(new TabListener<MapPdvTabFragment>(this, "mapa", MapPdvTabFragment.class)); 

    actionBar.addTab(tab1); 
    actionBar.addTab(tab2); 
} 

public ArrayList<Pdv> getListaPdv() { 
    return listaPdv; 
} 

public void setListaPdv(ArrayList<Pdv> listaPdv) { 
    this.listaPdv = listaPdv; 
} 

public static class TabListener<T extends Fragment> implements ActionBar.TabListener { 
    private Fragment mFragment; 
    private final Activity mActivity; 
    private final String mTag; 
    private final Class<T> mClass; 

    /** 
    * Constructor used each time a new tab is created. 
    * 
    * @param activity 
    *   The host Activity, used to instantiate the fragment 
    * @param tag 
    *   The identifier tag for the fragment 
    * @param clz 
    *   The fragment's Class, used to instantiate the fragment 
    */ 
    public TabListener(Activity activity, String tag, Class<T> clz) { 
     mActivity = activity; 
     mTag = tag; 
     mClass = clz; 
    } 

    /* The following are each of the ActionBar.TabListener callbacks */ 

    public void onTabSelected(ActionBar.Tab tab, FragmentTransaction ft) { 
     // Check if the fragment is already initialized 
     if (mFragment == null) { 
      // If not, instantiate and add it to the activity 
      mFragment = Fragment.instantiate(mActivity, mClass.getName()); 
      ft.add(android.R.id.content, mFragment, mTag); 
     } else { 
      // If it exists, simply attach it in order to show it 
      // ft.attach(mFragment); 
      ft.show(mFragment); 
     } 
    } 

    public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction ft) { 
     if (mFragment != null) { 
      // Detach the fragment, because another one is being attached 
      // ft.detach(mFragment); 
      ft.hide(mFragment); // Optimize map display 
     } 
    } 

    public void onTabReselected(ActionBar.Tab tab, FragmentTransaction ft) { 
     // User selected the already selected tab. Usually do nothing. 
    } 
} 

@Override 
public boolean onOptionsItemSelected(MenuItem item) { 
    switch (item.getItemId()) { 
    case android.R.id.home: 
     NavUtils.navigateUpFromSameTask(this); 
     return true; 
    case R.id.menu_sync: 
     DatabaseHandlerTienda db = new DatabaseHandlerTienda(this); 
     ArrayList<Pdv> lTiendas = db.getAllTiendas(); 

     // adbTienda.notifyDataSetChanged(); 
     // Toast.makeText(getActivity(), "test", Toast.LENGTH_LONG).show(); 
     return true; 

    default: 
     return super.onOptionsItemSelected(item); 
    } 
} 

@Override 
protected void refresh() { 
    LayoutInflater inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
    ImageView iv = (ImageView) inflater.inflate(R.layout.refresh_action_view, null); 

    Animation rotation = AnimationUtils.loadAnimation(this, R.anim.refresh); 
    rotation.setRepeatCount(Animation.INFINITE); 
    iv.startAnimation(rotation); 

    refreshItem.setActionView(iv); 
    // Sincronize: 

    SyncData sd = new SyncData(ctx); 
    sd.execute(); 
    // GET LISTVIEW FRAGMENT AND UPDATE VIEW 
} 

} 

Answer 1

你的菜單項應該最終調用一個抽象方法，用簽名就在BaseActivity並在每個子女Activity到BaseActivity（例如FragmentTabsPdv）中定義其實施。例如：

public abstract class BaseActivity { 
    protected abstract void refresh(); 
} 

和您的孩子Activity：

public class FragmentTabsPdv extends BaseActivity { 
    protected void refresh(){ 
     // This should update your Fragment 
    } 
} 

看起來你要調用的方法refresh()在AsyncTask的onPostExecute()。由於您在子活動中引用了片段，因此您應該可以從那裏適當刷新。

如果您需要查看顯示的Fragment，則應該可以使用Activity的FragmentManager這樣做。你的佈局xml應該有一個像FrameLayout來持有你的Fragments，對吧？可能與身份證android.R.id.content？用你的FragmentTabsPdv的FragmentManager獲得該內容的容器中的Fragment（您可以使用getFragmentManager()或getSupportFragmentManager()得到它）。然後你可以調用適當的方法。