Question

我有一个片段的工作模型，当我调试代码时，我看到片段onCreate被调用了4次。

以下是我的代码：的 MyFragmentActivity

class MyFragmentActivity extends FragmentActivity{

@Override
    public void onCreate(Bundle savedInstanceState) {
      if (savedInstanceState == null) {
        getSupportFragmentManager().beginTransaction().replace(fragmentID, new MyListFragmentt())
            .replace(detailFragmentID, new MyDetailFragment()).commit();
        }
}

@Override
    protected void onRestart() {
        getSupportFragmentManager().beginTransaction().replace(detailFragmentID, new MyDetailFragment()).commitAllowingStateLoss();
}

}

MyDetailFragment.class

class MyDetailFragment extends Fragment{

// has method like oncreate(),onCreateView(),onSaveInstanceState()
}

如何调用MyDetailFragment的oncreate？当我去其他一些活动然后回来然后只倾斜设备然后多次调用oncreate和MyDetailFragment的onSaveInstance状态。

我如何解决这个问题，我已经在SO上查了几篇文章，但它说我们需要使用HIDE,Show方法和其他东西？但对此有什么适当的灵魂？

修改

当我从之前的活动回来时，MyDetailFragment中的数据需要刷新。

Answer 1

    i think ur recreating fragments multiple times, u do new MyListFragment everytime on onCreate function, call findFragmentByTag to get the existing fragment and set that, if null (first time) then create one

/ 这里有一些代码配合，如果这不起作用，你的应用程序有单个片段更好地只创建xml并且只有一个片段标记，并在setContentView函数中设置xml * /

// declare following member variable MyFragment _fragment; // in onCreate function, call this method private void setupFragment() { _fragment = (MyFragment)getFragmentManager().findFragmentByTag("MyFragment"); if(null == _fragment) { _fragment = new MyFragment(); } // now do the fragment transaction FragmentTransaction trans = getFragmentManager().beginTransaction(); trans.add(containerId, _fragment, "MyFragment"); // here tag is important trans.commit(); }

Answer 2

试试这个

MyDetailFragment fragment = new MyDetailFragment();
@Override
    public void onCreate(Bundle savedInstanceState) {
      if (savedInstanceState == null) {

        getSupportFragmentManager().beginTransaction().replace(fragmentID, new MyListFragmentt())
            .replace(detailFragmentID, fragment).commit();
        }
}

@Override
    protected void onRestart() {
        if(fragment != null) {
        getSupportFragmentManager().beginTransaction().replace(detailFragmentID, fragment).commitAllowingStateLoss();
        }
}

片段：onCreate被调用4次

2 个答案: