的Android創建片段超過一次

Question

使用這個sample：我做我自己的片段保存tabhost和標籤內容：

public class TabsFragment extends Fragment 
    { 
     private static final String EXTRA_TAB = "EXTRA_TAB"; 

     private TabHost tabHost; 
     private TabManager tabManager; 
     private MaptrixFragmentActivity activity; 
     private Context context; 

     @Override 
     public void onAttach(Activity activity) 
     { 
      this.activity = (MaptrixFragmentActivity) activity; 
      this.context = activity; 
      super.onAttach(activity); 
     } 

     @Override 
     public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) 
     { 
      View view = inflater.inflate(R.layout.fragment_tabs, container, false); 
      tabHost = (TabHost)view.findViewById(android.R.id.tabhost); 
      tabHost.setup(); 
      tabManager = new TabManager(activity, tabHost, R.id.realtabcontent); 

      initTabs(); 

      if (savedInstanceState != null) 
      { 
       tabHost.setCurrentTabByTag(savedInstanceState.getString(EXTRA_TAB)); 
      } 
      return view; 
     } 

     private void initTabs() 
     { 
      // tab one 
      addTab(Fragment.class, null, R.drawable.icon1, Res.S(R.string.tab1)); 

      // I have not implement the tab fragment yet! 

      // tab two 
      addTab(Fragment.class, null, R.drawable.icon2, Res.S(R.string.tab2)); 
     } 

     private void addTab(Class<?> fragmenClass, Bundle bundle, int drawableId, String tag) 
     { 
      TabHost.TabSpec spec = tabHost.newTabSpec(tag); 
      View tabIndicator = LayoutInflater.from(context).inflate(R.layout.item_tab, tabHost.getTabWidget(), false); 
      ImageView icon = (ImageView) tabIndicator.findViewById(R.id.tab_image); 
      icon.setImageResource(drawableId); 
      spec.setIndicator(tabIndicator); 
      tabManager.addTab(spec, fragmenClass, bundle); 
     } 

     @Override 
     public void onSaveInstanceState(Bundle outState) 
     { 
      super.onSaveInstanceState(outState); 
      outState.putString(EXTRA_TAB, tabHost.getCurrentTabTag()); 
     } 

     public static class TabManager implements TabHost.OnTabChangeListener 
     { 
      private final FragmentActivity activity; 
      private final TabHost tabHost; 
      private final int containerID; 
      private final HashMap<String, TabInfo> tabs = new HashMap<String, TabInfo>(); 
      TabInfo lastTab; 
      TabFactory factory; 

      public TabManager(FragmentActivity activity, TabHost tabHost, int containerID) 
      { 
       this.activity = activity; 
       this.tabHost = tabHost; 
       this.containerID = containerID; 
       factory = new TabFactory(activity); 
       tabHost.setOnTabChangedListener(this); 
      } 

      public void addTab(TabHost.TabSpec tabSpec, Class<?> clss, Bundle args) 
      { 
       tabSpec.setContent(factory); 
       String tag = tabSpec.getTag(); 

       TabInfo info = new TabInfo(tag, clss, args); 

       info.fragment = activity.getSupportFragmentManager().findFragmentByTag(tag); 

       if (info.fragment != null && !info.fragment.isDetached()) 
       { 
        FragmentTransaction ft = activity.getSupportFragmentManager().beginTransaction(); 
        ft.detach(info.fragment); 
        ft.commit(); 
       } 

       tabs.put(tag, info); 
       tabHost.addTab(tabSpec); 
      } 

      @Override 
      public void onTabChanged(String tabId) 
      { 
       TabInfo newTab = tabs.get(tabId); 
       if (lastTab != newTab) 
       { 
        FragmentTransaction ft = activity.getSupportFragmentManager().beginTransaction(); 
        if (lastTab != null) { 
         if (lastTab.fragment != null) 
         { 
          ft.detach(lastTab.fragment); 
         } 
        } 
        if (newTab != null) 
        { 
         if (newTab.fragment == null) 
         { 
          newTab.fragment = Fragment.instantiate(activity, newTab.clss.getName(), newTab.args); 
          ft.add(containerID, newTab.fragment, newTab.tag); 
         } 
         else 
         { 
          ft.attach(newTab.fragment); 
         } 
        } 

        lastTab = newTab; 
        ft.commit(); 
       } 
      } 
     } 

     private static class TabInfo 
     { 
      private final String tag; 
      private final Class<?> clss; 
      private final Bundle args; 
      private Fragment fragment; 

      TabInfo(String _tag, Class<?> _class, Bundle _args) 
      { 
       tag = _tag; 
       clss = _class; 
       args = _args; 
      } 
     } 

     private static class TabFactory implements TabHost.TabContentFactory 
     { 
      private final Context mContext; 

      public TabFactory(Context context) 
      { 
       mContext = context; 
      } 

      @Override 
      public View createTabContent(String tag) 
      { 
       View v = new View(mContext); 
       v.setMinimumWidth(0); 
       v.setMinimumHeight(0); 
       return v; 
      } 
     } 
    } 

但onCreateView方法調用兩次或更多次設備時改變方向。

我FragmentActivity是：

public class MaptrixFragmentActivity extends FragmentActivity 
    { 
     @Override 
     protected void onCreate(Bundle savedInstanceState) 
     { 
      super.onCreate(savedInstanceState); 
      setContentView(R.layout.factivity); 

      replace(R.id.factivity_content, new TabsFragment(), false, false); 
     } 

     @Override 
     protected void onResume() 
     { 
      super.onResume(); 
     } 

     @Override 
     protected void onPause() 
     { 
      super.onPause(); 
     } 

     public void replace(int rootView, Fragment fragment) 
     { 
      replace(rootView, fragment, true, true); 
     } 

     public void replace(int rootView, Fragment fragment, boolean backStack) 
     { 
      replace(rootView, fragment, backStack, true); 
     } 

     public void replace(int rootView, Fragment fragment, boolean backStack, boolean animation) 
     { 
      FragmentTransaction transaction = getSupportFragmentManager().beginTransaction(); 
      if (animation) transaction.setCustomAnimations(R.anim.fragment_open, R.anim.fragment_close, R.anim.fragment_open_stack, R.anim.fragment_close_stack); 
      if (backStack) transaction.addToBackStack(null); 
      transaction.replace(R.id.factivity_maptrix_content, fragment); 
      transaction.commit(); 
     } 
    } 

爲什麼我有這樣的錯誤？

Answer 1

您也許可以將android:configChanges="keyboardHidden|orientation"添加到您的AndroidManifest.xml文件中。這可以避免在方向更改時重新創建活動，因此TabsFragment不會創建兩次。

<activity android:name="MaptrixFragmentActivity" android:configChanges="keyboardHidden|orientation"> 

查看this瞭解更多詳情。