java.lang.IllegalStateException: 无法在onSaveInstanceState之后执行此操作，FragmentTabHost

Question

MainActivity中有一个FragmentTabHost，并向其中添加了五个Fragments。 以下是初始化代码：

protected void onCreate(Bundle savedInstanceState) {
        mFragmentManager = getSupportFragmentManager();
        mTabHost = (FragmentTabHost) findViewById(android.R.id.tabhost);
        mTabHost.setup(this, mFragmentManager, android.R.id.tabcontent);
        // Home
        mTabHost.addTab(
                mTabHost.newTabSpec(TAB_TAG_HOME).setIndicator(
                        newTabItem(R.drawable.mi_selector_tab_home,
                                R.string.mi_tab_item_milian)),
                TabFateFragment.class, null);

        // Serach
        mTabHost.addTab(
                mTabHost.newTabSpec(TAB_TAG_SEARCH).setIndicator(
                        newTabItem(R.drawable.mi_selector_tab_search,
                                R.string.mi_navi_title_search)),
                TabSearchFragment.class, null);

        // Msg
        mTabHost.addTab(
                mTabHost.newTabSpec(TAB_TAG_MSG).setIndicator(
                        newTabItem(R.drawable.mi_selector_tab_msg,
                                R.string.mi_navi_title_msg)),
                TabMsgFragment.class, null);

        // Nearby
        mTabHost.addTab(
                mTabHost.newTabSpec(TAB_TAG_NEARBY).setIndicator(
                        newTabItem(R.drawable.mi_selector_tab_nearby,
                                R.string.mi_navi_title_nearby)),
                TabNearbyFragment.class, null);

        // Me
        mTabHost.addTab(
                mTabHost.newTabSpec(TAB_TAG_ME).setIndicator(
                        newTabItem(R.drawable.mi_selector_tab_me,
                                R.string.mi_navi_title_me)),
                TabMeFragment.class, null);
       ......
}

我已经阅读了这篇文章，但是在我的代码中找不到FragmentTransaction#commit()方法。

我尝试过在Activity的onSaveInstanceState(outState)方法中不调用super.onSaveInstanceState(Bundle outState)。

    @Override
    protected void onSaveInstanceState(Bundle outState) {
        // super.onSaveInstanceState(outState);
    }

这是崩溃日志：

java.lang.IllegalStateException: Can not perform this action after onSaveInstanceState
    at android.support.v4.app.FragmentManagerImpl.checkStateLoss(Unknown Source)
    at android.support.v4.app.FragmentManagerImpl.enqueueAction(Unknown Source)
    at android.support.v4.app.BackStackRecord.commitInternal(Unknown Source)
    at android.support.v4.app.BackStackRecord.commit(Unknown Source)
    at android.support.v4.app.FragmentTabHost.onAttachedToWindow(Unknown Source)
    at android.view.View.dispatchAttachedToWindow(View.java:12134)
    at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2453)
    at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2460)
    at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2460)
    at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2460)
    at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2460)
    at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1207)
    at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1004)
    at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5483)
    at android.view.Choreographer$CallbackRecord.run(Choreographer.java:778)
    at android.view.Choreographer.doCallbacks(Choreographer.java:591)
    at android.view.Choreographer.doFrame(Choreographer.java:561)
    at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:764)
    at android.os.Handler.handleCallback(Handler.java:730)
    at android.os.Handler.dispatchMessage(Handler.java:92)
    at android.os.Looper.loop(Looper.java:137)
    at android.app.ActivityThread.main(ActivityThread.java:5109)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:525)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
    at dalvik.system.NativeStart.main(Native Method)

- Scorpiuszjj

---

以上代码是否在您的活动的onCreate()方法中执行？您是否调用了setup()方法？ - logcat

我忘记把它粘贴到我的代码中了，mTabHost.setup(this, mFragmentManager, android.R.id.tabcontent); - Scorpiuszjj

我遇到了同样的问题。你解决了吗？ - MobileAppDeveloper

Answer 1

在 Activity 即将销毁之前，会调用 onSaveInstanceState 方法来保存 Activity 数据。在保存数据后向其中添加 Fragment 会导致错误发生。解决方法是将 commit() 方法替换为 commitAllowingStateLoss()，效果是相同的，但不会引起错误。

- John

---

但是，我的代码中没有FragmentTransaction#commit()。 - Scorpiuszjj

你可以放弃使用FragmentTabHost，而采用另一种方法，就像我的新答案一样。 - John

我只是在尝试弄清楚这个问题，而不是简单地尝试另一种实现。 - Scorpiuszjj

Answer 2

在使用addTab()之前，您必须调用setup()： http://developer.android.com/reference/android/support/v4/app/FragmentTabHost.html

- logcat

---

抱歉，我在addTab()之前调用了setup()，我忘记将它粘贴到我的代码中了，是我的失误。 mTabHost.setup(this, mFragmentManager, android.R.id.tabcontent); - Scorpiuszjj

Answer 3

使用Framelayout：

<FrameLayout

            android:id="@+id/tab_content"

            android:layout_width="match_parent"

            android:layout_height="match_parent"

            android:layout_gravity="bottom"

            android:orientation="vertical" />

并添加一个方法：

private synchronized void replaceFragment() {



        FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();

        // Workaround for Issue 42601:

        // https://code.google.com/p/android/issues/detail?id=42601

        fragmentTransaction.detach(tabFragments[previousTabIdx]).replace(R.id.tab_content, tabFragments[curTabIdx])

                .attach(tabFragments[curTabIdx]).commitAllowingStateLoss();

        previousTabIdx = curTabIdx;

    }

然后您可以使用commitAllowingStateLoss()方法。

- John