Question

我目前正在从 Android编程：大书呆子牧场指南学习Android。有一个名为 CriminalIntent 的应用程序，它引入了Fragments的概念。我按照作者的说法遵循了步骤，但仍然获得了运行时异常。这是代码

//由其他活动扩展的单个抽象活动类

incorporating fragments
        public abstract class SingleFragmentActivity extends Activity {
            protected abstract Fragment createFragment();
            @Override
            public void onCreate(Bundle savedInstanceState) {
                super.onCreate(savedInstanceState);
                setContentView(R.layout.activity_fragment);
                FragmentManager fm = getFragmentManager();
                Fragment fragment = fm.findFragmentById(R.id.fragmentContainer);
                if (fragment == null) {
                    fragment = createFragment();
                    fm.beginTransaction()
                            .add(R.id.fragmentContainer, fragment)
                            .commit();
                }
            }
        }

//此处是扩展上述类

的List活动

    public class CrimeListActivity extends SingleFragmentActivity {
        @Override
        protected Fragment createFragment() {
            return new CrimeListFragment();
        }
    }

//这是ListActivity使用的片段

public class CrimeListFragment extends ListFragment {

    private ArrayList<Crime> mCrimes;
    public CrimeListFragment() {
        // Required empty public constructor
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        getActivity().setTitle(R.string.crimes_title);
        mCrimes = CrimeLab.get(getActivity()).getCrimes();
        ArrayAdapter<Crime> adapter =
                new ArrayAdapter<Crime>(getActivity(),
                        android.R.layout.simple_list_item_1,
                        mCrimes);
        setListAdapter(adapter);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.fragment_crime_list, container, false);
    }


}

现在，布局：

// activity_fragment.xml

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/fragmentContainer"
    android:layout_width="match_parent"
    android:layout_height="match_parent"/>

和，
的 // fragment_crime_list.xml

<FrameLayout 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"
    tools:context="com.example.criminalintent.CrimeListFragment">
    <TextView android:layout_width="match_parent" android:layout_height="match_parent"
        android:text="@string/hello_blank_fragment" />

</FrameLayout>

我尝试过调试，但是我发现，在主要的Activity启动过程中会发生异常。

06-30 12:45:37.350  20494-20494/? I/art﹕ Not late-enabling -Xcheck:jni (already on)
06-30 12:45:37.398  20494-20494/? D/AndroidRuntime﹕ Shutting down VM
06-30 12:45:37.398  20494-20494/? E/AndroidRuntime﹕ FATAL EXCEPTION: main
    Process: com.example.criminalintent, PID: 20494
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.criminalintent/com.example.criminalintent.CrimeListActivity}: java.lang.RuntimeException: Content has view with id attribute 'android.R.id.list' that is not a ListView class
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2325)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2390)
            at android.app.ActivityThread.access$800(ActivityThread.java:151)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5257)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
     Caused by: java.lang.RuntimeException: Content has view with id attribute 'android.R.id.list' that is not a ListView class
            at android.app.ListFragment.ensureList(ListFragment.java:402)
            at android.app.ListFragment.onViewCreated(ListFragment.java:203)
            at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:908)
            at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1067)
            at android.app.BackStackRecord.run(BackStackRecord.java:834)
            at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1452)
            at android.app.Activity.performStart(Activity.java:6005)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2288)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2390)
            at android.app.ActivityThread.access$800(ActivityThread.java:151)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5257)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)

Answer 1

尝试将activity_fragment.xml更改为

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/fragmentContainer"
android:layout_width="match_parent"
android:layout_height="match_parent">
    <ListView
    android:id="@android:id/list"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"></ListView>
</FrameLayout>

java.lang.RuntimeException：Content具有id属性'android.R.id.list'的视图，该视图不是ListView类

1 个答案: