嵌套的Fragment出错——java.lang.IllegalStateException: Activity has been destroyed

Fragment

Fragment问题的处理：

11-23 23:40:26.037: E/AndroidRuntime(17186): FATAL EXCEPTION: main
11-23 23:40:26.037: E/AndroidRuntime(17186): java.lang.IllegalStateException: Activity has been destroyed
11-23 23:40:26.037: E/AndroidRuntime(17186):    at android.support.v4.app.FragmentManagerImpl.enqueueAction(FragmentManager.java:1376)
11-23 23:40:26.037: E/AndroidRuntime(17186):    at android.support.v4.app.BackStackRecord.commitInternal(BackStackRecord.java:595)
11-23 23:40:26.037: E/AndroidRuntime(17186):    at android.support.v4.app.BackStackRecord.commitAllowingStateLoss(BackStackRecord.java:578)

在使用嵌套的Fragment的时候，一定要检查执行嵌套的Fragment是否已经被Detach掉了，特别是在执行完网络操作或者其他耗时操作之后执行这种替换，但是不要使用Fragment的默认的isDetach()方法来检查，因为不一定有用，我们要自己来写这个逻辑：

• 执行替换的Fragment应该这么干

// Fragment是否已经被Detach了
private boolean detached = false;
@Override
public void onAttach(Activity activity) {
    super.onAttach(activity);
    // 在onAttached()中执行修改detach属性
    detached = false;
}
/**
 * 这个方法让外部能够访问detached属性
 */
public boolean isFragmentDetached(){
    return detached;
}
@Override
public void onDetach() {
    super.onDetach();
    // 在onDetach()中执行修改detach属性
    detached = true;
    try {
        Field childFragmentManager = Fragment.class
                .getDeclaredField("mChildFragmentManager");
        childFragmentManager.setAccessible(true);
        childFragmentManager.set(this, null);
    } catch (NoSuchFieldException e) {
        throw new RuntimeException(e);
    } catch (IllegalAccessException e) {
        throw new RuntimeException(e);
    }
}

• 在替换的时候执行以下的操作

/**
 * initBanner:初始化banner. <br/>
 * @author 
 * @param bannerList
 */
private void initBanner(ArrayList<Banner> bannerList) {
    // 如果已经detached了，则不再执行任何操作
    if(view.isFragmentDetached()){
        return;
    }
    view.addHeaderView();
    DebugLog.e("xinye", "###########hehe::::" + view.isFragmentDetached());
    ArrayList<Banner> bannerList1= new ArrayList<Banner>();
    String[] imgs = {
        "http://t1.qpic.cn/mblogpic/b62604c53322c5a31950/2000",
        "http://t1.qpic.cn/mblogpic/093bc5fc7cc898d05476/2000",
        "http://t2.qpic.cn/mblogpic/ce7ae27d0716d1d109e4/2000",
        "http://t1.qpic.cn/mblogpic/f576dd220da54c7081fa/2000"
    };
    for(int i = 0;i < 4;i++){
        Banner b = new Banner();
        b.setId(String.valueOf(i + 100));
        b.setImgWidth(720);
        b.setImgHeight(300);
        b.setImgUrl(imgs[i]);
        bannerList1.add(b);
    }
    FragmentManager manager = view.getChildCategoryFragmentManager();
    FragmentTransaction transaction = manager.beginTransaction();
    BannerFragment banner = new BannerFragment();
    banner.setBannerList(bannerList1);
    banner.setCategoryId(parentCategoryId);
    banner.setMainViewOperatorDelegate(view.getOperatorDelegate());
    transaction.replace(R.id.categoryChildHeaderView, banner);
    transaction.commitAllowingStateLoss();
}