用活动中的片段替换片段

Question

我有一个Activity，其Fragment方法中添加了onCreate（Frag A）。此Fragment包含我希望活动在默认情况下显示的UI元素。在按钮上点击片段A，我想用另一个显示进度条的片段（片段B）替换片段A.如果在显示Frag B时存在配置，则在调用activity的onCreate方法时不应添加Frag（A）。

我怎样才能实现这个目标？

就像在这个Facebook应用程序中完成的那样：

我尝试了很多方法：

1. 首先，我直接在活动的布局中添加了UI元素以及空的framelayout，因此在按钮上单击我隐藏UI元素并执行Fragment事务以放置包含我的进度条的片段在framelayout中，这工作正常，但如果有配置更改，则重新创建活动，然后我回到原点。

这就是我现在所拥有的。

MainActivity

    public class MainActivity extends FragmentActivity  {
Button button;
private ProgressDialog mpDialog;
boolean running;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    MainFragment fragment = new MainFragment();
        FragmentTransaction fragmentTransaction=    getSupportFragmentManager().beginTransaction();
        fragmentTransaction.add(R.id.wrapper, fragment).commit();

}



public void Click() {
    TaskFragment taskFragment = new TaskFragment();
    getSupportFragmentManager().beginTransaction().replace(R.id.wrapper, taskFragment).commit();

}


 }

MainFragment（持有UI元素）

    public class MainFragment extends Fragment {

View fView;
ProgressBar bar;
TextView textView;
Button button;
MainActivity activity = new MainActivity();
@Override
public void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setRetainInstance(true);
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    fView = inflater.inflate(R.layout.mainfragment, container, false);
    textView = (TextView) fView.findViewById(R.id.textview);
    button = (Button) fView.findViewById(R.id.button);
    clicked();
    return fView;
}


private void clicked() {
    // TODO Auto-generated method stub
    button.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View arg0) {
            // TODO Auto-generated method stub

            activity.Click();
        }
    });

}

   }

TaskFragment（显示进度条）

   public class TaskFragment extends Fragment{

View fview;
ProgressBar bar;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    // TODO Auto-generated method stub

    fview = inflater.inflate(R.layout.progressfragment, container, false);
    bar = (ProgressBar) fview.findViewById(R.id.sendingSmsProgress);
    return fview;
}

 }

我尝试切换片段时遇到的错误

  03-14 05:41:44.457: E/AndroidRuntime(11049): FATAL EXCEPTION: main
  03-14 05:41:44.457: E/AndroidRuntime(11049): java.lang.IllegalStateException: Activity has been destroyed
  03-14 05:41:44.457: E/AndroidRuntime(11049):  at android.support.v4.app.FragmentManagerImpl.enqueueAction(FragmentManager.java:1365)
  03-14 05:41:44.457: E/AndroidRuntime(11049):  at android.support.v4.app.BackStackRecord.commitInternal(BackStackRecord.java:595)
  03-14 05:41:44.457: E/AndroidRuntime(11049):  at android.support.v4.app.BackStackRecord.commit(BackStackRecord.java:574)
  03-14 05:41:44.457: E/AndroidRuntime(11049):  at com.example.test.MainActivity.Click(MainActivity.java:41)
  03-14 05:41:44.457: E/AndroidRuntime(11049):  at com.example.test.MainFragment$1.onClick(MainFragment.java:47)
  03-14 05:41:44.457: E/AndroidRuntime(11049):  at android.view.View.performClick(View.java:4102)
  03-14 05:41:44.457: E/AndroidRuntime(11049):  at android.view.View$PerformClick.run(View.java:17085)
  03-14 05:41:44.457: E/AndroidRuntime(11049):  at android.os.Handler.handleCallback(Handler.java:615)
  03-14 05:41:44.457: E/AndroidRuntime(11049):  at android.os.Handler.dispatchMessage(Handler.java:92)
  03-14 05:41:44.457: E/AndroidRuntime(11049):  at android.os.Looper.loop(Looper.java:155)
  03-14 05:41:44.457: E/AndroidRuntime(11049):  at android.app.ActivityThread.main(ActivityThread.java:5454)
  03-14 05:41:44.457: E/AndroidRuntime(11049):  at java.lang.reflect.Method.invokeNative(Native Method)
  03-14 05:41:44.457: E/AndroidRuntime(11049):  at java.lang.reflect.Method.invoke(Method.java:511)
  03-14 05:41:44.457: E/AndroidRuntime(11049):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1029)
  03-14 05:41:44.457: E/AndroidRuntime(11049):  at  com.android.internal.os.ZygoteInit.main(ZygoteInit.java:796)
  03-14 05:41:44.457: E/AndroidRuntime(11049):  at dalvik.system.NativeStart.main(Native Method)

Answer 1

如果要从片段中替换片段，请使用

getActivity().getSupportFragmentManager().beginTransaction()
            .replace(R.id.frame, new DialogFragment()).commit();