我正在使用以下代码从互联网获取数据并打开它。它工作得很好，但如果我更改选项卡并返回旧选项卡会出错。例如，如果在开始时我是选项卡 1，然后转到选项卡 2 效果很好，但如果我返回选项卡 1，则会出现错误
public class MainMenu extends FragmentActivity
{
private TabHost tHost;
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.main_menu);
tHost = (TabHost) findViewById(android.R.id.tabhost);
tHost.setup();
/** Defining Tab Change Listener event. This is invoked when tab is changed */
TabHost.OnTabChangeListener tabChangeListener = new TabHost.OnTabChangeListener()
{
@Override
public void onTabChanged(String tabId)
{
FragmentManager fm = getSupportFragmentManager();
PrayerTimes prayerFragment = (PrayerTimes) fm.findFragmentByTag("prayerTimes");
CompassActivity qiblaFragment = (CompassActivity) fm.findFragmentByTag("qibla");
Settings settingFragment = (Settings) fm.findFragmentByTag("settings");
FragmentTransaction ft = fm.beginTransaction();
/** Detaches the androidfragment if exists */
if(prayerFragment!=null)
ft.detach(prayerFragment);
if(qiblaFragment!=null)
ft.detach(qiblaFragment);
if(settingFragment!=null)
ft.detach(qiblaFragment);
/** If current tab is android */
if(tabId.equals("prayerTimes"))
{
if(prayerFragment == null)
{
/** Create AndroidFragment and adding to fragmenttransaction */
ft.add(R.id.realtabcontent,new PrayerTimes(), "prayerTimes");
}
else
{
/** Bring to the front, if already exists in the fragmenttransaction */
ft.attach(prayerFragment);
}
}
else if (tabId.equals("qibla"))
{
if( qiblaFragment == null)
{
/** Create AppleFragment and adding to fragmenttransaction */
ft.add(R.id.realtabcontent,new CompassActivity(), "qibla");
}
else
{
/** Bring to the front, if already exists in the fragmenttransaction */
ft.attach(qiblaFragment);
}
}
else if(tabId.equals("settings"))
{
if( settingFragment == null)
{
/** Create AppleFragment and adding to fragmenttransaction */
ft.add(R.id.realtabcontent,new Settings(), "settings");
}
else
{
/** Bring to the front, if already exists in the fragmenttransaction */
ft.attach(settingFragment);
}
}
ft.commit();
}
};
/** Setting tabchangelistener for the tab */
tHost.setOnTabChangedListener(tabChangeListener);
/** Defining tab builder for Andriod tab */
TabHost.TabSpec tSpecPrayer = tHost.newTabSpec("prayerTimes");
tSpecPrayer.setIndicator("Prayer Times");
tSpecPrayer.setContent(new MyTabContent(getBaseContext()));
tHost.addTab(tSpecPrayer);
/** Defining tab builder for Apple tab */
TabHost.TabSpec tSpecQibla = tHost.newTabSpec("qibla");
tSpecQibla.setIndicator("Qibla");
tSpecQibla.setContent(new MyTabContent(getBaseContext()));
tHost.addTab(tSpecQibla);
TabHost.TabSpec tSpecSettings = tHost.newTabSpec("settings");
tSpecSettings.setIndicator("Settings");
tSpecSettings.setContent(new MyTabContent(getBaseContext()));
tHost.addTab(tSpecSettings);
}
}
错误是
2-11 12:21:28.245: E/AndroidRuntime(992): FATAL EXCEPTION: main
02-11 12:21:28.245: E/AndroidRuntime(992): java.lang.IllegalStateException: Recursive entry to executePendingTransactions
02-11 12:21:28.245: E/AndroidRuntime(992): at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1416)
02-11 12:21:28.245: E/AndroidRuntime(992): at android.support.v4.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:461)
02-11 12:21:28.245: E/AndroidRuntime(992): at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:141)
02-11 12:21:28.245: E/AndroidRuntime(992): at android.support.v4.view.ViewPager.populate(ViewPager.java:1012)
02-11 12:21:28.245: E/AndroidRuntime(992): at android.support.v4.view.ViewPager.setCurrentItemInternal(ViewPager.java:523)
02-11 12:21:28.245: E/AndroidRuntime(992): at android.support.v4.view.ViewPager.setCurrentItemInternal(ViewPager.java:495)
02-11 12:21:28.245: E/AndroidRuntime(992): at android.support.v4.view.ViewPager.onRestoreInstanceState(ViewPager.java:1221)
02-11 12:21:28.245: E/AndroidRuntime(992): at android.view.View.dispatchRestoreInstanceState(View.java:12088)
02-11 12:21:28.245: E/AndroidRuntime(992): at android.view.ViewGroup.dispatchRestoreInstanceState(ViewGroup.java:2582)
02-11 12:21:28.245: E/AndroidRuntime(992): at android.view.ViewGroup.dispatchRestoreInstanceState(ViewGroup.java:2588)
02-11 12:21:28.245: E/AndroidRuntime(992): at android.view.View.restoreHierarchyState(View.java:12066)
02-11 12:21:28.245: E/AndroidRuntime(992): at android.support.v4.app.Fragment.restoreViewState(Fragment.java:417)
02-11 12:21:28.245: E/AndroidRuntime(992): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:933)
02-11 12:21:28.245: E/AndroidRuntime(992): at android.support.v4.app.FragmentManagerImpl.attachFragment(FragmentManager.java:1264)
02-11 12:21:28.245: E/AndroidRuntime(992): at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:672)
02-11 12:21:28.245: E/AndroidRuntime(992): at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1444)
02-11 12:21:28.245: E/AndroidRuntime(992): at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:429)
02-11 12:21:28.245: E/AndroidRuntime(992): at android.os.Handler.handleCallback(Handler.java:725)
02-11 12:21:28.245: E/AndroidRuntime(992): at android.os.Handler.dispatchMessage(Handler.java:92)
02-11 12:21:28.245: E/AndroidRuntime(992): at android.os.Looper.loop(Looper.java:137)
02-11 12:21:28.245: E/AndroidRuntime(992): at android.app.ActivityThread.main(ActivityThread.java:5039)
02-11 12:21:28.245: E/AndroidRuntime(992): at java.lang.reflect.Method.invokeNative(Native Method)
02-11 12:21:28.245: E/AndroidRuntime(992): at java.lang.reflect.Method.invoke(Method.java:511)
02-11 12:21:28.245: E/AndroidRuntime(992): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
02-11 12:21:28.245: E/AndroidRuntime(992): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
02-11 12:21:28.245: E/AndroidRuntime(992): at dalvik.system.NativeStart.main(Native Method)