Question

我收到了一个错误：

为标记片段

找到了意外的名称空间前缀“xmlns”

代表行

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

in

  <?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>

有谁知道什么是错的？

Answer 1

删除此

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

表示xml中的片段

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类似的以下帖子

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看起来您正在寻找带有片段的标签。因此，请尝试以下内容并根据您的要求进行修改。

示例：

我设置min sdk是11

MainActivity.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

  }

    }
}

Framgent 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;
 }

}

片段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;
 }

}

片段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;
 }

}

片段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>

片段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>

片段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>

快照

enter image description here

Answer 2

您需要在文档元素上使用xmlns=架构属性，并且可能还需要xmlns:xsi属性，例如：

xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

[这是来自web.xml，xmlns此处不适用于您的命名空间。]

Answer 3

在tabhost布局文件中，更改父TabHost标记代码，如下所示

 <TabHost   xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:id="@android:id/tabhost"
        >

xmlns声明必须是第一个然后必须使用它。至于我担心在布局文件中第二次定义xmlns不会影响或创建错误但我希望你因错误的声明而面临问题

Answer 4

这可能适用于您的具体问题，也可能不适用。我遇到了同样的问题。 Eclipse有时可能比较挑剔。我做的是：备份原始文件。然后复制粘贴回导致错误的代码。重新编译，错误消失了。

为标记片段找到了意外的名称空间前缀“xmlns”

4 个答案: