Question

我遇到动态片段问题。如果我不改变方向，它工作正常。当我改变方向时，我点击ListView项目。这不是改变textview。

这是DynamicActivity类

public class DynamicActivity extends Activity implements FragmentCoordinator{

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

    FragmentManager fragmentManager = getFragmentManager();
    FragmentTransaction transaction = fragmentManager.beginTransaction();
    ListContentFragment listContentFragment = new ListContentFragment();
    DetailsContentFragment detailsContentFragment = new DetailsContentFragment();
    transaction.add(R.id.listContainer, listContentFragment,"listContent");
    transaction.add(R.id.detailsContainer, detailsContentFragment,"detailsContent");
    transaction.commit();

}

@Override
public void onSetContentDetails(int index) {
    FragmentManager fragmentManager = getFragmentManager();

    DetailsContentFragment detailsContentFragment = (DetailsContentFragment)fragmentManager.findFragmentByTag("detailsContent");

    detailsContentFragment.setContentDetails(index);
}

}

和DetailsContentFragment类

public class DetailsContentFragment extends Fragment {

TextView lbMess;
String[] array;
int saveIndex;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

    View v = inflater.inflate(R.layout.details_content_fragment, container,false);
    array = getResources().getStringArray(R.array.list_details);
    lbMess = (TextView)v.findViewById(R.id.lbDetails);

    int currentIndex = savedInstanceState == null ? 0 : savedInstanceState.getInt("indexContent",0);
    setContentDetails(currentIndex);

    return v;
}

@Override
public void onSaveInstanceState(Bundle outState) {
    outState.putInt("indexContent", saveIndex);
}

public void setContentDetails(int index) {
    saveIndex = index;
    lbMess.setText(array[saveIndex]);
}
}

我有调试但它没有任何错误。请给我一些建议

Answer 1

我发现问题是：当系统因运行时配置更改而销毁并重新创建活动时，活动会自动进行重新实例化现有的片段。

对于在活动布局中声明的“静态”片段，这不是问题。

但对于“动态”片段，我需要测试这种情况，以防止创建片段的第二个实例。

我检查传递给我的活动的Bundle参数onCreate（）是否为空。

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

    if(savedInstanceState == null)
    {
        FragmentManager fragmentManager = getFragmentManager();
        FragmentTransaction transaction = fragmentManager.beginTransaction();
        ListContentFragment listContentFragment = new ListContentFragment();
        DetailsContentFragment detailsContentFragment = new DetailsContentFragment();
        transaction.add(R.id.listContainer, listContentFragment,"listContent");
        transaction.add(R.id.detailsContainer, detailsContentFragment,"detailsContent");
        transaction.commit();
    }

}

它工作正常。我认为对有同样问题的人有帮助。

Android - 方向更改时的动态片段问题

1 个答案: