如何进行fragment中的来回切换？

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问：Ijaz Ahmed

我想要对fragment中的fragment进行操作，在按后退按钮的时候出现了问题。应用程序主屏幕上有很多按钮，按下每个按钮都会出现新的fragment（它也被包含在另一个fragment内）。按下按钮1（已替换fragment）,可以进行动态的添加或者是替换片段。如果按下按钮后，再去按它，就会得到：

1 2	"Duplicate id 0x7f05000a, tag null, or parent id 0x7f050009 with another fragment for com........ fragmentname"

这意味着已经添加过fragment，有谁可以帮我完成fragment的相关设定，并顺利的完成来回切换？

如下是，MainActiviy的代码,它可以控制动态添加/替换fragment：

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public class FragmentInsideFragmentTestActivity extends Activity {    private Button button1;  private Button button2;  private Button button3;  private Button button4;      /** Called when the activity is first created. */ @Override  public void onCreate(Bundle savedInstanceState) {  super.onCreate(savedInstanceState);  setContentView(R.layout.main);    button1 =(Button) this.findViewById(R.id.button1);  button1.setOnClickListener(new View.OnClickListener() {      public void onClick(View view) {          onButtonClick(view);            }  });    button2 =(Button) this.findViewById(R.id.button2);  button2.setOnClickListener(new View.OnClickListener() {      public void onClick(View view) {          onButtonClick(view);            }  });    button3 =(Button) this.findViewById(R.id.button3);  button3.setOnClickListener(new View.OnClickListener() {      public void onClick(View view) {          onButtonClick(view);            }  });    button4 =(Button) this.findViewById(R.id.button4);  button4.setOnClickListener(new View.OnClickListener() {      public void onClick(View view) {          onButtonClick(view);            }  });     }    public void onButtonClick(View v) {          Fragment fg;          switch (v.getId()) {          case R.id.button1:                  fg=FirstFragment.newInstance();                  replaceFragment(fg);                  break;          case R.id.button2:                  fg=SecondFragment.newInstance();                  replaceFragment(fg);                  break;          case R.id.button3:                  fg=FirstFragment.newInstance();                  replaceFragment(fg);                  break;          case R.id.button4:                  fg=SecondFragment.newInstance();                  replaceFragment(fg);                  break;          }  }    private void replaceFragment(Fragment newFragment) {    FragmentTransaction trasection =  getFragmentManager().beginTransaction();  if(!newFragment.isAdded()){          try{                  //FragmentTransaction trasection =          getFragmentManager().beginTransaction();          trasection.replace(R.id.linearLayout2, newFragment);          trasection.addToBackStack(null);          trasection.commit();            }catch (Exception e) {                          // TODO: handle exception                   //AppConstants.printLog(e.getMessage());                    }  }else          trasection.show(newFragment);       }   }

如下是Layout : main.xml

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<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent"     <LinearLayout android:id="@+id/linearLayout1"           android:layout_width="match_parent"           android:layout_height="wrap_content"           android:orientation="horizontal">           <Button android:layout_width="wrap_content"                   android:id="@+id/button1"                   android:layout_height="wrap_content"                   android:text="Button1"></Button>           <Button android:text="Button2"                   android:id="@+id/button2"                   android:layout_width="wrap_content"                   android:layout_height="wrap_content"></Button>           <Button android:text="Button3"                   android:id="@+id/button3"                   android:layout_width="wrap_content"                   android:layout_height="wrap_content"></Button>           <Button android:text="Button4"                   android:id="@+id/button4"                   android:layout_width="wrap_content"                   android:layout_height="wrap_content"></Button>   </LinearLayout>    <LinearLayout android:id="@+id/linearLayout2"   android:layout_width="match_parent"    android:layout_height="wrap_content"   android:orientation="horizontal"></LinearLayout>     </LinearLayout>

以上就是我遇到的问题，希望大家可以为我解答。

答：CommonsWare

（最佳答案）

你可以用getChildFragmentManager()进行fragment嵌套操作，但这也意味着你的Android支持包版本的API级别要在11-16之间。主要是因为，即使在配置上存在fragment的自带版本，但是也未必可以支getChildFragmentManager()。

答：Napolean

fragment可以嵌套在其它的fragment中，但每次调用onDestroyView()时，你都需要从parent Fragment中删掉它，然后将它添加到OnCreateView()中的parent Fragment。具体方法如下：

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@Override     public void onDestroyView()     {                 FragmentManager mFragmentMgr= getFragmentManager();         FragmentTransaction mTransaction = mFragmentMgr.beginTransaction();                 Fragment childFragment =mFragmentMgr.findFragmentByTag("qa_fragment")         mTransaction.remove(childFragment);         mTransaction.commit();         super.onDestroyView();     }

答：Vetal.lebed

我的解决办法是，使用支持库（Support library）和ViewPager。你可以禁用一些不必要的程序，具体方法如下：

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public class TestFragment extends Fragment{ @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {     View v = inflater.inflate(R.layout.frag, container, false);     final ArrayList<Fragment> list = new ArrayList<Fragment>();       list.add(new TrFrag());     list.add(new TrFrag());     list.add(new TrFrag());       ViewPager pager = (ViewPager) v.findViewById(R.id.pager);     pager.setAdapter(new FragmentPagerAdapter(getActivity().getSupportFragmentManager()) {         @Override         public Fragment getItem(int i) {             return list.get(i);         }           @Override         public int getCount() {             return list.size();         }     });     return v; }

原文链接：http://stackoverflow.com/questions/6672066/fragment-inside-fragment?rq=1

http://android.9tech.cn/news/2013/1202/39041.html