我正在使用 Fragment 并且当我更改设备的方向时。如果最初是纵向的，当我将其更改为横向时，我的应用程序就会崩溃。我在这里添加了 logcat。我浏览了许多链接，但找不到正确的答案。
请帮我解决这个问题。
谢谢
public class PageViewActivity extends FragmentActivity {
private ViewPager viewPager;
private NoticePageAdapter noticePageAdapter;
private TextView titleText;
private int pageIndex;
private static int restTime = 0;
private long lastTime;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_CUSTOM_TITLE);
setContentView(R.layout.activity_page_view);
getWindow().setFeatureInt(Window.FEATURE_CUSTOM_TITLE, R.layout.window_title2);
titleText = (TextView) findViewById(R.id.title2);
titleText.setText(R.string.app_name);
// Create the adapter that will return a fragment for each of the three
// primary sections of the app.
noticePageAdapter = new NoticePageAdapter(getSupportFragmentManager());
// Set up the ViewPager with the sections adapter.
viewPager = (ViewPager) findViewById(R.id.viewpager);
Intent intent = getIntent();
pageIndex = intent.getIntExtra("notice_position", 0);
viewPager.setAdapter(noticePageAdapter);
viewPager.setCurrentItem(pageIndex, true);
lastTime = System.currentTimeMillis();
//Check the rest time. If it exceed the 30 sec then finish the activity.
new CheckTimeThread().start();
}
/**
* A {@link FragmentPagerAdapter} that returns a fragment corresponding to
* one of the sections/tabs/pages.
*/
class NoticePageAdapter extends FragmentPagerAdapter {
public NoticePageAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int position) {
Fragment fragment = new NoticeFragment();
Bundle args = new Bundle();
args.putInt(NoticeFragment.TEMPLATE_POSITION, position + 1);
fragment.setArguments(args);
return fragment;
}
@Override
public int getCount() {
return NoticeData.templateId.length;
}
}
/**
* A Notice fragment representing a notices of the app, but that simply
* displays notices
*/
public class NoticeFragment extends Fragment {
public static final String TEMPLATE_POSITION = "template_position";
private TextView noticeHeaderTextView;
private TextView noticeContentTextView;
private ImageView noticeImageView;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
int templatePosition = getArguments().getInt(TEMPLATE_POSITION);
int templateId = 0;
int tempVar;
tempVar = templatePosition - 1;
templateId = Integer.parseInt(NoticeData.templateId[tempVar]);
int res = R.layout.first_template;
switch (templateId) {
case 1:
res = R.layout.first_template;
break;
case 2:
res = R.layout.second_template;
break;
case 3:
res = R.layout.third_template;
break;
case 4:
res = R.layout.fourth_template;
break;
default:
break;
}
View rootView = inflater.inflate(res, container, false);
noticeHeaderTextView = (TextView)rootView.findViewById(R.id.noticeHeading);
noticeHeaderTextView.setText(Html.fromHtml(NoticeData.noticeHeading[tempVar]));
noticeContentTextView = (TextView)rootView.findViewById(R.id.noticeContent);
noticeContentTextView.setText(Html.fromHtml(NoticeData.noticeContent[tempVar]));
noticeImageView = (ImageView)rootView.findViewById(R.id.noticeImageView);
UrlImageViewHelper.setUrlDrawable(noticeImageView, NoticeData.imagesURL[tempVar]);
DisplayMetrics metrics = getResources().getDisplayMetrics();
int width = metrics.widthPixels;
if(templateId == 3) {
noticeImageView.getLayoutParams().width = width / 2;
}
else if(templateId == 2) {
noticeHeaderTextView.getLayoutParams().width = width/2;
noticeContentTextView.getLayoutParams().width = width/2;
}
RelativeLayout relativeLayout = (RelativeLayout)rootView.findViewById(R.id.relativeLayout);
relativeLayout.setOnTouchListener(new OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
resetRestTime();
return false;
}
});
return rootView;
}
}
}
错误跟踪：
06-24 18:24:36.501: E/AndroidRuntime(11863): FATAL EXCEPTION: main
06-24 18:24:36.501: E/AndroidRuntime(11863): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.noticeboard/com.noticeboard.PageViewActivity}: android.support.v4.app.Fragment$InstantiationException: Unable to instantiate fragment com.noticeboard.PageViewActivity$NoticeFragment: make sure class name exists, is public, and has an empty constructor that is public
06-24 18:24:36.501: E/AndroidRuntime(11863): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1970)
06-24 18:24:36.501: E/AndroidRuntime(11863): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1995)
06-24 18:24:36.501: E/AndroidRuntime(11863): at android.app.ActivityThread.handleRelaunchActivity(ActivityThread.java:3365)
06-24 18:24:36.501: E/AndroidRuntime(11863): at android.app.ActivityThread.access$700(ActivityThread.java:128)
06-24 18:24:36.501: E/AndroidRuntime(11863): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1165)
06-24 18:24:36.501: E/AndroidRuntime(11863): at android.os.Handler.dispatchMessage(Handler.java:99)
06-24 18:24:36.501: E/AndroidRuntime(11863): at android.os.Looper.loop(Looper.java:137)
06-24 18:24:36.501: E/AndroidRuntime(11863): at android.app.ActivityThread.main(ActivityThread.java:4514)
06-24 18:24:36.501: E/AndroidRuntime(11863): at java.lang.reflect.Method.invokeNative(Native Method)
06-24 18:24:36.501: E/AndroidRuntime(11863): at java.lang.reflect.Method.invoke(Method.java:511)
06-24 18:24:36.501: E/AndroidRuntime(11863): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:790)
06-24 18:24:36.501: E/AndroidRuntime(11863): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:557)
06-24 18:24:36.501: E/AndroidRuntime(11863): at dalvik.system.NativeStart.main(Native Method)
06-24 18:24:36.501: E/AndroidRuntime(11863): Caused by: android.support.v4.app.Fragment$InstantiationException: Unable to instantiate fragment com.noticeboard.PageViewActivity$NoticeFragment: make sure class name exists, is public, and has an empty constructor that is public
06-24 18:24:36.501: E/AndroidRuntime(11863): at android.support.v4.app.Fragment.instantiate(Fragment.java:399)
06-24 18:24:36.501: E/AndroidRuntime(11863): at android.support.v4.app.FragmentState.instantiate(Fragment.java:97)
06-24 18:24:36.501: E/AndroidRuntime(11863): at android.support.v4.app.FragmentManagerImpl.restoreAllState(FragmentManager.java:1760)
06-24 18:24:36.501: E/AndroidRuntime(11863): at android.support.v4.app.FragmentActivity.onCreate(FragmentActivity.java:200)
06-24 18:24:36.501: E/AndroidRuntime(11863): at com.noticeboard.PageViewActivity.onCreate(PageViewActivity.java:40)
06-24 18:24:36.501: E/AndroidRuntime(11863): at android.app.Activity.performCreate(Activity.java:4465)
06-24 18:24:36.501: E/AndroidRuntime(11863): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1053)
06-24 18:24:36.501: E/AndroidRuntime(11863): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1934)
06-24 18:24:36.501: E/AndroidRuntime(11863): ... 12 more
06-24 18:24:36.501: E/AndroidRuntime(11863): Caused by: java.lang.InstantiationException: can't instantiate class com.noticeboard.PageViewActivity$NoticeFragment; no empty constructor
06-24 18:24:36.501: E/AndroidRuntime(11863): at java.lang.Class.newInstanceImpl(Native Method)
06-24 18:24:36.501: E/AndroidRuntime(11863): at java.lang.Class.newInstance(Class.java:1319)
06-24 18:24:36.501: E/AndroidRuntime(11863): at android.support.v4.app.Fragment.instantiate(Fragment.java:388)
06-24 18:24:36.501: E/AndroidRuntime(11863): ... 19 more