FragmentTabHost "活动已被破坏"

Question

我有 3 个片段选项卡，片段 1、片段 2 和片段 3。我在 fragment2 中创建了另一个片段选项卡。问题是每当我重新选择包含片段选项卡的片段 2 时，我的应用程序就会崩溃，并显示如下所示的 LOGCAT。我在这个链接Getting the error "Java.lang.IllegalStateException Activity has been destroyed" when using tabs with ViewPager 上关注了stackoverflow 中的一个问题，但它似乎也不起作用。另外，我是否导入了正确的库“import java.lang.reflect.Field;”？

fragment2.java

import com.actionbarsherlock.app.SherlockFragment;
import android.os.Bundle;
import android.support.v4.app.FragmentTabHost;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class Fragment2 extends SherlockFragment{
     private FragmentTabHost mTabHost;

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                Bundle savedInstanceState) {

            mTabHost = new FragmentTabHost(getSherlockActivity());
            mTabHost.setup(getSherlockActivity(), getChildFragmentManager(), R.layout.fragmenttab2);

            mTabHost.addTab(mTabHost.newTabSpec("simple").setIndicator("Simple"),
                    Fragment1.class, null);
            mTabHost.addTab(mTabHost.newTabSpec("contacts").setIndicator("Contacts"),
                     Fragment2.class, null);
            mTabHost.addTab(mTabHost.newTabSpec("custom").setIndicator("Custom"),
                     Fragment3.class, null);

            return mTabHost;
        }

        @Override
        public void onDestroyView() {
            super.onDestroyView();
            mTabHost = null;
        }


}

LogCat：

 07-22 16:18:50.668: E/AndroidRuntime(29774): FATAL EXCEPTION: main
07-22 16:18:50.668: E/AndroidRuntime(29774): java.lang.IllegalStateException: Activity has been destroyed
07-22 16:18:50.668: E/AndroidRuntime(29774):    at android.support.v4.app.FragmentManagerImpl.enqueueAction(FragmentManager.java:1342)
07-22 16:18:50.668: E/AndroidRuntime(29774):    at android.support.v4.app.BackStackRecord.commitInternal(BackStackRecord.java:595)
07-22 16:18:50.668: E/AndroidRuntime(29774):    at android.support.v4.app.BackStackRecord.commit(BackStackRecord.java:574)
07-22 16:18:50.668: E/AndroidRuntime(29774):    at android.support.v4.app.FragmentTabHost.onAttachedToWindow(FragmentTabHost.java:278)
07-22 16:18:50.668: E/AndroidRuntime(29774):    at android.view.View.dispatchAttachedToWindow(View.java:9953)
07-22 16:18:50.668: E/AndroidRuntime(29774):    at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2198)
07-22 16:18:50.668: E/AndroidRuntime(29774):    at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2206)
07-22 16:18:50.668: E/AndroidRuntime(29774):    at android.view.ViewGroup.addViewInner(ViewGroup.java:3376)
07-22 16:18:50.668: E/AndroidRuntime(29774):    at android.view.ViewGroup.addView(ViewGroup.java:3208)
07-22 16:18:50.668: E/AndroidRuntime(29774):    at android.view.ViewGroup.addView(ViewGroup.java:3165)
07-22 16:18:50.668: E/AndroidRuntime(29774):    at android.view.ViewGroup.addView(ViewGroup.java:3145)
07-22 16:18:50.668: E/AndroidRuntime(29774):    at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:922)
07-22 16:18:50.668: E/AndroidRuntime(29774):    at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1088)
07-22 16:18:50.668: E/AndroidRuntime(29774):    at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:682)
07-22 16:18:50.668: E/AndroidRuntime(29774):    at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1444)
07-22 16:18:50.668: E/AndroidRuntime(29774):    at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:429)
07-22 16:18:50.668: E/AndroidRuntime(29774):    at android.os.Handler.handleCallback(Handler.java:605)
07-22 16:18:50.668: E/AndroidRuntime(29774):    at android.os.Handler.dispatchMessage(Handler.java:92)
07-22 16:18:50.668: E/AndroidRuntime(29774):    at android.os.Looper.loop(Looper.java:137)
07-22 16:18:50.668: E/AndroidRuntime(29774):    at android.app.ActivityThread.main(ActivityThread.java:4507)
07-22 16:18:50.668: E/AndroidRuntime(29774):    at java.lang.reflect.Method.invokeNative(Native Method)
07-22 16:18:50.668: E/AndroidRuntime(29774):    at java.lang.reflect.Method.invoke(Method.java:511)
07-22 16:18:50.668: E/AndroidRuntime(29774):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:980)
07-22 16:18:50.668: E/AndroidRuntime(29774):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:747)
07-22 16:18:50.668: E/AndroidRuntime(29774):    at dalvik.system.NativeStart.main(Native Method)

Answer 1

编写此代码时：

   Field childFragmentManager = Fragment2.class.getDeclaredField("mChildFragmentManager");

表示你想得到你在 Fragment2 中声明的文件。

我可以在 Fragment2 中看到 mChildFragmentManager 字段。

如果你确定这个文件是在超类中声明的，你应该使用 Fragment2.class.getField

Answer 2

试试这个 childFragmentManager

childeFragmentManager = getChildFragmentManager().

它是在 4.2 发布后添加到支持库中的，因为在此之前不支持嵌套片段。

来源 http://developer.android.com/about/versions/android-4.2.html#NestedFragments