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我是开发 Android 程序的新手，一直坚持尝试完成介绍片段的 Professional Android 4 书中的练习。我收到以下错误：

InflateException: Binary XML file line #6: Error inflating class fragment

以下是我的主要活动 java 程序：

package com.example.todolist;
import java.util.ArrayList;
import android.app.Activity;
import android.app.FragmentManager;
import android.os.Bundle;
import android.widget.ArrayAdapter;

public class MainActivity extends Activity 
implements NewItemFragment.OnNewItemAddedListener {
private ArrayAdapter<String> aa;
private ArrayList<String> todoItems;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    // Get references to the Fragments

    FragmentManager fm = getFragmentManager();
    ToDoListFragment todoListFragment =                        
    (ToDoListFragment)fm.findFragmentById(R.id.ToDoListFragment);
  aa = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, todoItems);
  todoListFragment.setListAdapter(aa);
  @Override
public void onNewItemAdded(String newItem) {
    // TODO Auto-generated method stub
    todoItems.add(newItem);
    aa.notifyDataSetChanged();
}

}

ToDoListFragment 类如下所示：

package com.example.todolist;
import android.app.ListFragment;

public class ToDoListFragment extends ListFragment{

}

下面是我的 NewItemFragment 类。

package com.example.todolist;

import android.app.Activity;
import android.support.v4.app.Fragment;
import android.view.KeyEvent;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.EditText;


public class NewItemFragment extends Fragment{

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.new_item_fragment, container, false);

    final EditText myEditText = (EditText)view.findViewById(R.id.myEditText);

    myEditText.setOnKeyListener(new View.OnKeyListener() {
        public boolean onKey(View v, int keyCode, KeyEvent event) {
          if(event.getAction() == KeyEvent.ACTION_DOWN)
              if((keyCode == KeyEvent.KEYCODE_DPAD_CENTER) ||  
                  (keyCode == KeyEvent.KEYCODE_ENTER)) {
                  String newItem = myEditText.getText().toString();
                  onNewItemAddedListener.onNewItemAdded(newItem);
                  myEditText.setText("");
                  return true;
        } 
      return false;

}
    });
    return view;
}

public interface OnNewItemAddedListener {
    public void onNewItemAdded(String newItem);

}

private OnNewItemAddedListener onNewItemAddedListener;

@Override
public void onAttach(Activity activity) {
    super.onAttach(activity);

    try {
        onNewItemAddedListener = (OnNewItemAddedListener)activity;
    } catch (ClassCastException e) {
        throw new ClassCastException(activity.toString());
    }
}

}

下面是我的 activity_main.xml 文件：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<fragment android:name="com.paad.todolist.NewItemFragment"
    android:id="@+id/NewItemFragment" 
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:hint="@string/addItemHint"

    />
<fragment android:name="com.paad.todolist.ToDoListFragment" 
   android:id="@+id/ToDoListFragment"
   android:layout_width="match_parent"
   android:layout_height="wrap_content"

   />
  </LinearLayout>

最后，这是我的 new_itemFragment xml 文件：

<EditText xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/myEditText" 
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:hint="@string/addItemHint"
    />

如果有人能告诉我为什么会出现膨胀片段错误，我将不胜感激。我尝试使用 import android.support.v4.app.FragmentManager 但没有奏效并尝试使用 android.support.v4.app.ListFragment 也没有奏效。多年来我一直在使用其他语言进行编程，但到目前为止，使用 Eclipse 对我来说，Android 确实是一个挑战。他们有更好的 IDE 来开发 Android 项目吗？

我尝试导入 android.support.v4.app 片段类，但是当我这样做时 getFragmentManager 函数未解决。下面是 logcat 的转储。

  02-21 20:53:27.769: E/AndroidRuntime(1280): java.lang.RuntimeException: Unable to     start activity    ComponentInfo{com.example.todolist/com.example.todolist.MainActivity}: android.view.InflateException: Binary XML file line #6: Error inflating class fragment
  02-21 20:53:27.769: E/AndroidRuntime(1280): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
 02-21 20:53:27.769: E/AndroidRuntime(1280):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
 02-21 20:53:27.769: E/AndroidRuntime(1280):    at android.app.ActivityThread.access$600(ActivityThread.java:141)
 02-21 20:53:27.769: E/AndroidRuntime(1280):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
 02-21 20:53:27.769: E/AndroidRuntime(1280):    at android.os.Handler.dispatchMessage(Handler.java:99)
 02-21 20:53:27.769: E/AndroidRuntime(1280):    at android.os.Looper.loop(Looper.java:137)
 02-21 20:53:27.769: E/AndroidRuntime(1280):    at android.app.ActivityThread.main(ActivityThread.java:5039)
 02-21 20:53:27.769: E/AndroidRuntime(1280):    at java.lang.reflect.Method.invokeNative(Native Method)
 02-21 20:53:27.769: E/AndroidRuntime(1280):    at java.lang.reflect.Method.invoke(Method.java:511)
 02-21 20:53:27.769: E/AndroidRuntime(1280):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
 02-21 20:53:27.769: E/AndroidRuntime(1280):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
 02-21 20:53:27.769: E/AndroidRuntime(1280):    at dalvik.system.NativeStart.main(Native Method)
 02-21 20:53:27.769: E/AndroidRuntime(1280): Caused by: android.view.InflateException: Binary XML file line #6: Error inflating class fragment
 02-21 20:53:27.769: E/AndroidRuntime(1280):    at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:704)
 02-21 20:53:27.769: E/AndroidRuntime(1280):    at android.view.LayoutInflater.rInflate(LayoutInflater.java:746)
 02-21 20:53:27.769: E/AndroidRuntime(1280):    at android.view.LayoutInflater.inflate(LayoutInflater.java:489)
 02-21 20:53:27.769: E/AndroidRuntime(1280):    at android.view.LayoutInflater.inflate(LayoutInflater.java:396)
 02-21 20:53:27.769: E/AndroidRuntime(1280):    at android.view.LayoutInflater.inflate(LayoutInflater.java:352)
 02-21 20:53:27.769: E/AndroidRuntime(1280):    at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:270)
 02-21 20:53:27.769: E/AndroidRuntime(1280):    at android.app.Activity.setContentView(Activity.java:1881)
 02-21 20:53:27.769: E/AndroidRuntime(1280):    at com.example.todolist.MainActivity.onCreate(MainActivity.java:20)
 02-21 20:53:27.769: E/AndroidRuntime(1280):    at android.app.Activity.performCreate(Activity.java:5104)
 02-21 20:53:27.769: E/AndroidRuntime(1280):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
 02-21 20:53:27.769: E/AndroidRuntime(1280):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
 02-21 20:53:27.769: E/AndroidRuntime(1280):    ... 11 more
 02-21 20:53:27.769: E/AndroidRuntime(1280): Caused by: android.app.Fragment$InstantiationException: Unable to instantiate fragment com.paad.todolist.NewItemFragment: make sure class name exists, is public, and has an empty constructor that is public
 02-21 20:53:27.769: E/AndroidRuntime(1280):    at android.app.Fragment.instantiate(Fragment.java:592)
 02-21 20:53:27.769: E/AndroidRuntime(1280):    at android.app.Fragment.instantiate(Fragment.java:560)
 02-21 20:53:27.769: E/AndroidRuntime(1280):    at android.app.Activity.onCreateView(Activity.java:4709)
 02-21 20:53:27.769: E/AndroidRuntime(1280):    at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:680)
 02-21 20:53:27.769: E/AndroidRuntime(1280):    ... 21 more
 02-21 20:53:27.769: E/AndroidRuntime(1280): Caused by:        java.lang.ClassNotFoundException: Didn't find class "com.paad.todolist.NewItemFragment" on  path: /data/app/com.example.todolist-1.apk
 02-21 20:53:27.769: E/AndroidRuntime(1280):    at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:65)
 02-21 20:53:27.769: E/AndroidRuntime(1280):    at java.lang.ClassLoader.loadClass(ClassLoader.java:501)
 02-21 20:53:27.769: E/AndroidRuntime(1280):    at java.lang.ClassLoader.loadClass(ClassLoader.java:461)

运行调试器，我发现在这些指令中抛出了异常：
aa = new ArrayAdapter(this, android.R.layout.simple_list_item_1, todoItems);
todoListFragment.setListAdapter(aa);

我注意到 todoItems 的值为 null 所以我想知道该元素是否必须用一个值初始化。

4

3 回答 3

2

它在这里寻找一个片段：com.paad.todolist.NewItemFragment

这就是您的 xml 文件中的内容。

但是，实际执行的包在这里：

package com.example.todolist;

因此，您需要将 xml 文件更改为：

<fragment android:name="com.example.todolist.NewItemFragment"

也检查一下ToDoListFragment。

于 2013-02-21T22:18:40.447 回答
0

使用新的片段类，将导入的包 android.app.Fragment\ 替换为 android.support.v4.app.Fragment 它会帮助你。

于 2013-05-24T11:13:53.513 回答
-2

MainActivity 必须扩展 FragmentActivity 类

于 2013-05-08T12:40:23.280 回答