如何附加（）和分離（）而不是添加（）和刪除（）以保存片段視圖

Question

我爲ActionBar以下代碼：

private class MyTabListener implements ActionBar.TabListener 
{ 
    private Fragment mFragment; 
    private final Activity mActivity; 
    private final String mFrag; 

    public MyTabListener(Activity activity, String fragName) 
    { 
     mActivity = activity; 
     mFrag = fragName; 
    } 

    @Override 
    public void onTabReselected(Tab tab, FragmentTransaction ft) 
    { 
     // TODO Auto-generated method stub 

    } 

    @Override 
    public void onTabSelected(Tab tab, FragmentTransaction ft) 
    { 
     mFragment = Fragment.instantiate(mActivity, mFrag); 
     ft.add(android.R.id.content, mFragment); 
    } 

    @Override 
    public void onTabUnselected(Tab tab, FragmentTransaction ft) 
    { 
     ft.remove(mFragment); 
     mFragment = null; 
    } 
} 

我有那些Tab片段和開關內的一些文本框標籤之間強制應用程序丟失我添加到這些文本框的任何數據。取而代之的add和remove，我想用attach和detach節省了片段狀態。

如何完成的代碼中，我已經有了？

更新：

現在，該代碼如下所示：

private class MyTabListener implements ActionBar.TabListener 
{ 
    private Fragment mFragment; 
    private final Activity mActivity; 
    private final String mFrag; 

    public MyTabListener(Activity activity, String fragName) 
    { 
     mActivity = activity; 
     mFrag = fragName; 
    } 

    @Override 
    public void onTabReselected(Tab tab, FragmentTransaction ft) 
    { 
     // TODO Auto-generated method stub 

    } 

    @Override 
    public void onTabSelected(Tab tab, FragmentTransaction ft) 
    { 
     //mFragment = Fragment.instantiate(mActivity, mFrag); 
     //ft.add(android.R.id.content, mFragment); 
      mFragment = mActivity.getSupportFragmentManager().findFragmentByTag(mFrag); 
      if(mFragment == null) { 
      mFragment = Fragment.instantiate(mActivity, mClass.getName()); 
      ft.add(android.R.id.content, mFragment, mFrag); 
      } else { 
      ft.attach(mFragment); 
      } 
    } 

    @Override 
    public void onTabUnselected(Tab tab, FragmentTransaction ft) 
    { 
     //ft.remove(mFragment); 
     //mFragment = null; 
      if (mFragment != null) { 
       ft.detach(mFragment); 
       } 
    } 
} 

而且我得到一個錯誤的下面一行：

mFragment = mActivity.getSupportFragmentManager().findFragmentByTag(mFrag); 

錯誤：

The method getSupportFragmentManager() is undefined for the type Activity 

Answer 1

而不是重寫代碼，您可以使用SharedPreferences臨時存儲正在顯示的變量。

在你離開的標籤的onDestroy方法，只需添加您的變量的喜好，並檢索它們，當你重新輸入標籤。

@Override 
public void onDestroy(){ 
    super.onDestroy(); 
    Log.i("OnDestroy", "Logged"); 
    SharedPreferences prefs = getActivity().getSharedPreferences("name", Context.MODE_PRIVATE); 
    Editor editor = prefs.edit(); 
    editor.putString("stringName", stringToStore); 
    editor.commit(); 
}