Question

我在使用Fragments和backstack工作时遇到了麻烦。

我有一个带有FrameLayout的布局，用于存放各种片段和另一个片段：

<LinearLayout
xmlns:tools="http://schemas.android.com/tools"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
xmlns:android="http://schemas.android.com/apk/res/android">

<FrameLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/filterableListContainer"
    android:layout_weight="50">
</FrameLayout>


<fragment class="com.facetoe.remotempd.fragments.PlayerBarFragment"
          android:id="@+id/playerBarFragment"
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:layout_weight="1"
          tools:layout="@layout/player_bar"/>
</LinearLayout>

当我启动使用此布局的Activity时，我将片段添加到FrameLayout，如下所示：

    @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_test);
    if (findViewById(R.id.filterableListContainer) != null) {

        // However, if we're being restored from a previous state,
        // then we don't need to do anything and should return or else
        // we could end up with overlapping fragments.
        if (savedInstanceState != null) {
            return;
        }

        // Create a new Fragment to be placed in the activity layout
        ArtistListFragment listFragment = new ArtistListFragment();

        // Add the fragment to the 'fragment_container' FrameLayout
        FragmentTransaction ft = getFragmentManager().beginTransaction();
        ft.replace(R.id.filterableListContainer, listFragment);
        ft.addToBackStack(null);
        ft.commit();
    } else {
        Log.e(TAG, "Couldn't find filterableListFragment");
    }

}

当用户点击某个项目时，我尝试用以下代码替换该片段：

            ArtistAlbumsListFragment fragment = new ArtistAlbumsListFragment(getActivity(), albums);
        FragmentTransaction ft = getFragmentManager().beginTransaction();
        ft.replace(R.id.filterableListContainer, fragment);
        ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
        ft.addToBackStack(null);
        ft.commit();

然而，当我按下后退按钮时，我会返回主屏幕。谁能告诉我哪里出错了？

Answer 1

好的我修好了。当我在Intellij中创建Activity时，它创建了一个ActionBarActivity的子类。删除ActionBarActivity并将其替换为Activity会使片段转换按预期工作。

Answer 2

不要添加ft.addToBackStack（null）这个语句。

ArtistAlbumsListFragment fragment = new ArtistAlbumsListFragment（getActivity（），albums）; FragmentTransaction ft = getFragmentManager（）。beginTransaction（）; ft.replace（R.id.filterableListContainer，fragment）; ft.setTransition（FragmentTransaction.TRANSIT_FRAGMENT_OPEN）; ft.commit（）;

片段未添加到backstack

2 个答案: