android - 为标记 fragment 找到意外的命名空间前缀 "xmlns"

Question

我收到一个错误:

为标记 fragment 找到意外的 namespace 前缀“xmlns”

对于行

 <fragment xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"

在

  <?xml version="1.0" encoding="utf-8"?>
        <TabHost android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:id="@android:id/tabhost"
        xmlns:android="http://schemas.android.com/apk/res/android"
        >
        <TabWidget
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:id="@android:id/tabs"
        />
         <FrameLayout
         android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:id="@android:id/tabcontent"
         >
         <fragment xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        android:id="@+id/item_list"
        android:name="com.example.storeitemfinder.ItemListFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginLeft="16dp"
        android:layout_marginRight="16dp"
        tools:context=".ItemListActivity"
        tools:layout="@android:layout/list_content" />
         </FrameLayout>
        </TabHost>

谁知道这是怎么回事？

Answer 1

删除这个

 xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:tools="http://schemas.android.com/tools"

对于xml中的 fragment

http://developer.android.com/guide/topics/resources/layout-resource.html

根元素可以是 ViewGroup、View 或元素，但必须只有一个根元素，并且它必须包含带有 android 命名空间的 xmlns:android 属性，如图所示。

为了确保我刚刚浏览了以下相似的帖子

Unexpected namespace prefix "xmlns" for tag fragment

Unexpected namespace prefix "xmlns" found for tag LinearLayout

Unexpected namespace prefix "xmlns" found for tag ListView

编辑:

从您在评论中发布的链接来看，您正在寻找的是带有 fragment 的标签。因此，请尝试以下操作并根据您的要求进行修改。

示例:

我已将最小 sdk 设置为 11

主 Activity .java

public class MainActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        final ActionBar actionBar = getActionBar();
        actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

        Tab tabA = actionBar.newTab();
        tabA.setText("Tab A");
        tabA.setTabListener(new TabListener<MyFragmentA>(this, "Tag A", MyFragmentA.class));
        actionBar.addTab(tabA);

        Tab tabB = actionBar.newTab();
        tabB.setText("Tab B");
        tabB.setTabListener(new TabListener<MyFragmentB>(this, "Tag B", MyFragmentB.class));
        actionBar.addTab(tabB);

        Tab tabC = actionBar.newTab();
        tabC.setText("Tab C");
        tabC.setTabListener(new TabListener<MyFragmentC>(this, "Tag C", MyFragmentC.class));
        actionBar.addTab(tabC);

        if (savedInstanceState != null) {
            int savedIndex = savedInstanceState.getInt("SAVED_INDEX");
            getActionBar().setSelectedNavigationItem(savedIndex);
        }

    }

 @Override
 protected void onSaveInstanceState(Bundle outState) {
  // TODO Auto-generated method stub
  super.onSaveInstanceState(outState);
  outState.putInt("SAVED_INDEX", getActionBar().getSelectedNavigationIndex());
 }

 public static class TabListener<T extends Fragment> 
     implements ActionBar.TabListener{

        private final Activity myActivity;
        private final String myTag;
        private final Class<T> myClass;

        public TabListener(Activity activity, String tag, Class<T> cls) {
            myActivity = activity;
            myTag = tag;
            myClass = cls;
        }

  @Override
  public void onTabSelected(Tab tab, FragmentTransaction ft) {

   Fragment myFragment = myActivity.getFragmentManager().findFragmentByTag(myTag);

   // Check if the fragment is already initialized
         if (myFragment == null) {
             // If not, instantiate and add it to the activity
             myFragment = Fragment.instantiate(myActivity, myClass.getName());
             ft.add(android.R.id.content, myFragment, myTag);
         } else {
             // If it exists, simply attach it in order to show it
             ft.attach(myFragment);
         }

  }

  @Override
  public void onTabUnselected(Tab tab, FragmentTransaction ft) {

   Fragment myFragment = myActivity.getFragmentManager().findFragmentByTag(myTag);

   if (myFragment != null) {
             // Detach the fragment, because another one is being attached
             ft.detach(myFragment);
         }

  }

  @Override
  public void onTabReselected(Tab tab, FragmentTransaction ft) {
   // TODO Auto-generated method stub

  }

    }
}

fragment A

public class MyFragmentA extends Fragment {

 @Override
 public View onCreateView(LayoutInflater inflater, ViewGroup container,
   Bundle savedInstanceState) {
  View myFragmentView = inflater.inflate(R.layout.fragment_a, container, false);
  return myFragmentView;
 }

}

fragment B

public class MyFragmentB extends Fragment {

 @Override
 public View onCreateView(LayoutInflater inflater, ViewGroup container,
   Bundle savedInstanceState) {
  View myFragmentView = inflater.inflate(R.layout.fragment_b, container, false);
  return myFragmentView;
 }

}

fragment C

public class MyFragmentC extends Fragment {

 @Override
 public View onCreateView(LayoutInflater inflater, ViewGroup container,
   Bundle savedInstanceState) {
  View myFragmentView = inflater.inflate(R.layout.fragment_c, container, false);
  return myFragmentView;
 }

}

fragment A

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
   android:layout_width="fill_parent"
   android:layout_height="fill_parent"
   android:orientation="vertical" >
   <TextView
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
       android:text="It's Fragment A" />
   <ImageView
       android:layout_width="match_parent"
       android:layout_height="match_parent"
       android:src="@drawable/ic_launcher"/>
</LinearLayout>

fragment b xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
   android:layout_width="fill_parent"
   android:layout_height="fill_parent"
   android:orientation="vertical" >
   <TextView
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
       android:text="It's Fragment B" />
   <ImageView
       android:layout_width="match_parent"
       android:layout_height="match_parent"
       android:scaleType="center"
       android:src="@drawable/ic_launcher"/>
</LinearLayout>

fragment c xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
   android:layout_width="fill_parent"
   android:layout_height="fill_parent"
   android:orientation="vertical" >
   <TextView
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
       android:text="It's Fragment C" />

</LinearLayout>

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