我尝试使用不同的信息创建一个ListFragment,但不起作用,我不知道为什么。 这是我的ListFragment类
public class Countries extends ListFragment{
private ArrayAdapter<String> arrayCountryAdapter;
private Countries.OnFragmentInteractionListener mCallback;
public Countries(){
//Public Constructor
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
}
@Override
public void onCreate(Bundle savedInstanceState){
CountryController countryController = new CountryController();
String[] countries = countryController.getCountries();
if(countries != null) {
arrayCountryAdapter = new ArrayAdapter<String>(getActivity(), android.R.layout.simple_list_item_1, countries);
setListAdapter(arrayCountryAdapter);
}
else{
//If the list are null
setEmptyText("Server Error, try again later");
}
}
@Override
public void onListItemClick(ListView l, View v, int position, long id){
//Notify the parent Activity of selected item
Toast.makeText(getActivity(), "Click on the Element", Toast.LENGTH_LONG).show();
mCallback.onArticleSelected(position);
//Set the item as checked
getListView().setItemChecked(position, true);
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
mCallback = (OnFragmentInteractionListener) activity;
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString()
+ " must implement OnFragmentInteractionListener");
}
}
@Override
public void onDetach() {
super.onDetach();
mCallback = null;
}
public interface OnFragmentInteractionListener {
public void onArticleSelected(int position);
}
}
这是片段的布局
<LinearLayout
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.twopaneapplication.Fragments.Countries">
<ListView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/listViewCountries"
android:layout_gravity="left|top" />
<TextView
android:id="@android:id/empty"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/empty_list"
/>
</LinearLayout>
这是与之前的ListFragment相关联的活动
public class CountryActivity extends Activity implements Countries.OnFragmentInteractionListener{
@Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_country);
}
public void onArticleSelected(int position){
//Make an Intent for call the other activity
}
}
他们的布局
<LinearLayout
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">
<fragment
android:id="@+id/countries"
android:name="com.example.twopaneapplication.Fragments.Countries"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
tools:layout="@layout/fragment_countries"/>
</LinearLayout>
当点击某个具有意图的元素时,我评论的ListFragment是从另一个ListFragment调用的
MainActivity.java
...
public void onArticleSelected(int position){
Intent intent = new Intent(this, CountryActivity.class);
startActivity(intent);
}
这是异常的堆栈跟踪
12-24 14:30:55.436 836-836/com.example.twopaneapplication E/AndroidRuntime﹕ FATAL EXCEPTION: main
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.twopaneapplication/com.example.twopaneapplication.Activities.CountryActivity}: android.view.InflateException: Binary XML file line #7: Error inflating class fragment
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2059)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
at android.app.ActivityThread.access$600(ActivityThread.java:130)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4745)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
at dalvik.system.NativeStart.main(Native Method)
Caused by: android.view.InflateException: Binary XML file line #7: Error inflating class fragment
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:704)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:746)
at android.view.LayoutInflater.inflate(LayoutInflater.java:489)
at android.view.LayoutInflater.inflate(LayoutInflater.java:396)
at android.view.LayoutInflater.inflate(LayoutInflater.java:352)
at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:256)
at android.app.Activity.setContentView(Activity.java:1867)
at com.example.twopaneapplication.Activities.CountryActivity.onCreate(CountryActivity.java:16)
at android.app.Activity.performCreate(Activity.java:5008)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
at android.app.ActivityThread.access$600(ActivityThread.java:130)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4745)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at com.example.twopaneapplication.Controllers.CountryController.getCountries(CountryController.java:42)
at com.example.twopaneapplication.Fragments.Countries.onCreate(Countries.java:35)
at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:796)
at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1013)
at android.app.FragmentManagerImpl.addFragment(FragmentManager.java:1112)
at android.app.Activity.onCreateView(Activity.java:4664)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:680)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:746)
at android.view.LayoutInflater.inflate(LayoutInflater.java:489)
at android.view.LayoutInflater.inflate(LayoutInflater.java:396)
at android.view.LayoutInflater.inflate(LayoutInflater.java:352)
at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:256)
at android.app.Activity.setContentView(Activity.java:1867)
at com.example.twopaneapplication.Activities.CountryActivity.onCreate(CountryActivity.java:16)
at android.app.Activity.performCreate(Activity.java:5008)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
at android.app.ActivityThread.access$600(ActivityThread.java:130)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4745)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
at dalvik.system.NativeStart.main(Native Method)
希望有人可以帮助我,我一整天都坚持这一点。 谢谢!