Android app闪退后fragment重叠bug解决方法

方法一

通过注释掉这句话，这样主 Activity 因为种种原因被回收的时候就不会保存之前的 fragment state

@Override
protectedvoidonSaveInstanceState(Bundle outState) {
//如果用以下这种做法则不保存状态，再次进来的话会显示默认tab
//总是执行这句代码来调用父类去保存视图层的状态
//super.onSaveInstanceState(outState);
}

方法二、（推荐使用）

重写onAttachFragment，重新让新的Fragment指向了原本未被销毁的fragment，它就是onAttach方法对应的Fragment对象

@Override
    public void onAttachFragment(Fragment fragment) {
        if (tab1 == null && fragment instanceof Tab1Fragment)
            tab1 = fragment;
        if (tab2 == null && fragment instanceof Tab2Fragment)
            tab2 = fragment;
        if (tab3 == null && fragment instanceof Tab3Fragment)
            tab3 = fragment;
        if (tab4 == null && fragment instanceof Tab4Fragment)
            tab4 = fragment;
    }

方法三

同样是阻止系统恢复Fragment state，在FragmentActivity保存所有Fragment状态前把Fragment从FragmentManager中移除掉。

protected void onSaveInstanceState(Bundle outState) {
        FragmentTransaction transaction = fm.beginTransaction();
        transaction.remove(tab1);
        transaction.remove(tab2);
        transaction.remove(tab3);
        transaction.remove(tab4);
        transaction.commitAllowingStateLoss();
        super.onSaveInstanceState(outState);
    }