我遇到了问题,我无法解决.在我的应用程序中,我有一个导航抽屉定义如下：
activity_main.xml中
<android.support.v4.widget.DrawerLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<!-- 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" />
在MainActivity类中,我通常使用setContentView传递这个xml：
MainActivity.java
setContentView(R.layout.activity_main);
mNavigationDrawerFragment = (NavigationDrawerFragment)
getSupportFragmentManager().findFragmentById(R.id.navigation_drawer);
在我的NavigationDrawerFragment onCreateView上,我通常用它来膨胀它的xml：
NavigationDrawerFragment.java
public View onCreateView(LayoutInflater inflater,ViewGroup container,Bundle savedInstanceState) {
View root = (View)inflater.inflate(R.layout.fragment_navigation_drawer,null,false);
mDrawerListView = (ListView)root.findViewById(R.id.drawer_list_view);
mDrawerListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent,View view,int position,long id) {
selectItem(position);
}
});
这是fragment_navigation_drawer.xml：
fragment_navigation_drawer.xml
<LinearLayout
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:android="http://schemas.android.com/apk/res/android">
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="10dp">
<ImageView
android:id="@+id/profile_picture"
android:layout_width="50dp"
android:layout_height="50dp"
android:layout_alignParentLeft="true"/>
<TextView
android:id="@+id/user_name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="10dp"
android:layout_toRightOf="@id/profile_picture"
android:textStyle="bold"
android:textSize="15sp" />
<TextView
android:id="@+id/user_mail"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@id/user_name"
android:layout_alignLeft="@id/user_name"
android:fontFamily="sans-serif-light" />
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:src="@android:drawable/ic_menu_close_clear_cancel"/>
</RelativeLayout>
<ListView 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:choiceMode="singleChoice"
android:id="@+id/drawer_list_view"
android:dividerHeight="0dp"
android:background="@color/navigation_drawer_background" />
当我运行代码时,我在MainActivity的setContentView上得到一个例外：
Caused by: java.lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child's parent first.
我认为NavigationDrawer布局有问题.我究竟做错了什么？
编辑：我将我的布局更改为：
<android.support.v4.widget.DrawerLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<!-- The main content view -->
<FrameLayout
android:id="@+id/content_frame"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
<!-- The navigation drawer -->
<FrameLayout
android:id="@+id/left_drawer_frame"
android:layout_width="@dimen/navigation_drawer_dimension"
android:layout_height="match_parent"
android:layout_gravity="start"
android:background="@android:color/white"/>
所以使用FrameLayout,在我的活动中我使用：
mFragment = new Fragment();
getSupportFragmentManager()
.beginTransaction()
.replace(R.id.content_frame,mFragment)
.commit();
我用这个膨胀片段：
View root = inflater.inflate(R.layout.fragment_main,container,false);
这一切似乎都有效
解决方法
迟到总比不到好.
查看您的代码(变量名称,布局结构等)我假设您使用的是Android Studio,并且您使用Android Studio“创建项目”向导提供的“导航抽屉”模板创建了项目.
如果上述假设为真,那么您的问题就在于NavigationDrawerFragment的onCreateView.你必须从onCreateView返回膨胀的视图,在这种特殊情况下你应该返回的是root而不是mDrawerListView
public View onCreateView(LayoutInflater inflater,long id) {
selectItem(position);
}
});
return root;
// This is wrong
// return mDrawerListView;
}
希望这可以帮助.
