Android 个片段 - 指定的 child 已经有一个 parent。您必须先在 child 的 parent 上调用 removeView()

Question

我正在尝试创建一个带有导航抽屉的应用程序。在我尝试在我的导航抽屉片段中的列表视图上方添加另一个 TextView 之前，它运行良好。然后当我尝试在我的 HomeActivity 中设置 ContentView 时它给出了这个异常：

java.lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child's parent first.

以下是所有相关代码：

fragment_navigation_drawer.xml：（fb_name textview 是我需要添加的。）

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

<TextView
    android:id="@+id/fb_name"
    android:layout_width="@dimen/navigation_drawer_width"
    android:layout_height="60dp"
    android:text="First Last"
    android:textColor="@android:color/white" />

<ListView
    android:id="@+id/nav_drawer"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#000000"
    android:choiceMode="singleChoice"
    android:divider="#ffcdcdcd"
    android:paddingTop="40dp"
    tools:context=".NavigationDrawerFragment" />

</LinearLayout>

这是我膨胀片段的地方-

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    ViewGroup group = (ViewGroup) inflater.inflate(
            R.layout.fragment_navigation_drawer, container, false);
    mDrawerListView = (ListView) group.findViewById(R.id.nav_drawer);
    mDrawerListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            selectItem(position);
        }
    });

    ArrayList<DrawerItem> drawerItems = new ArrayList<DrawerItem>();

    DrawerItem drawerItem1 = new DrawerItem("Home", R.drawable.home);
    DrawerItem drawerItem2 = new DrawerItem("Start a Contest", R.drawable.hand_point);
    DrawerItem drawerItem3 = new DrawerItem("All Contests", R.drawable.briefcase);
    DrawerItem drawerItem4 = new DrawerItem("My Contests", R.drawable.binoculars);
    DrawerItem drawerItem5 = new DrawerItem("Login", R.drawable.home);

    drawerItems.add(drawerItem1);
    drawerItems.add(drawerItem2);
    drawerItems.add(drawerItem3);
    drawerItems.add(drawerItem4);
    drawerItems.add(drawerItem5);

    DrawerAdapter adapter = new DrawerAdapter(getActivity(), drawerItems);
    mDrawerListView.setAdapter(adapter);
    mDrawerListView.setItemChecked(mCurrentSelectedPosition, true);
    return mDrawerListView;
}

这是 setContentView 抛出异常的 activity onCreate() -

    @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_home); //This is where the exception occurs

    mNavigationDrawerFragment = (NavigationDrawerFragment)
            getSupportFragmentManager().findFragmentById(R.id.navigation_drawer);
    mTitle = getTitle();

    // Set up the drawer.
    mNavigationDrawerFragment.setUp(
            R.id.navigation_drawer,
            (DrawerLayout) findViewById(R.id.drawer_layout));
}

这是我的 DrawerLayout 所在的位置 -

<!-- A DrawerLayout is intended to be used as the top-level content view using match_parent for both width and height to consume the full space available. -->

<!-- As the main content view, the view below consumes the entire
     space available using match_parent in both dimensions. -->
<FrameLayout android:id="@+id/container" android:layout_width="match_parent"
    android:layout_height="match_parent" />

<!-- android:layout_gravity="start" tells DrawerLayout to treat
     this as a sliding drawer on the left side for left-to-right
     languages and on the right side for right-to-left languages.
     If you're not building against API 17 or higher, use
     android:layout_gravity="left" instead. -->
<!-- The drawer is given a fixed width in dp and extends the full height of
     the container. -->
<fragment android:id="@+id/navigation_drawer"
    android:layout_width="@dimen/navigation_drawer_width" android:layout_height="match_parent"
    android:layout_gravity="start"
    android:name="com.labs.thinkdifferent.voice.NavigationDrawerFragment"
    tools:layout="@layout/fragment_navigation_drawer" />

</android.support.v4.widget.DrawerLayout>

Answer 1

我会试一试并建议你得到错误，因为你在 onCreateView() 而不是 group 中 return mDrawerListView。来自 onCreateView() 视图的 returned 本身附加到另一个视图层次结构，在这种情况下这是不可能的，因为从 XML 布局它已经有一个父级 ViewGroup.

我看不出有什么可以阻止在 onCreateView() 中 returning group。

Android 个片段 - 指定的 child 已经有一个 parent。您必须先在 child 的 parent 上调用 removeView()

Android fragments - The specified child already has a parent. You must call removeView() on the child's parent first

android

android-fragments

navigation-drawer