Question

MainActivity中包含FragmentTabHost，并且有五个片段添加到此FragmentTabHost中。这是初始化代码

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);
       ......
}

我已阅读此article，在我的代码中找不到FragmentTransaction＃commit（）。

我试过在Activity.onSaveInstanceState（outState）中调用super.onSaveInstanceState（Bundle outState）

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

以下是崩溃日志

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)

Answer 1

onSaveInstanceState方法在Activity即将被销毁之前调用，以保存Activity数据。在保存数据后导致错误将片段添加到它。解决方法是用commitAllowingStateLoss替换commit（）方法（），效果是一样的。

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

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;

    }

然后你可以使用commitAllowingStateLoss（）方法。

java.lang.IllegalStateException：在onSaveInstanceState之后无法执行此操作，FragmentTabHost

3 个答案: