Question

我有2个片段，当我替换第二个片段并按下后退按钮时，我的第一个片段显示为空白，这是我的代码

    Fragment fragment = new MovieDetails();
            Bundle args = new Bundle();
            args.putString("background", item.getBackg());
            args.putString("thumb", item.getThumb());
            args.putString("id", item.getCode());
            fragment.setArguments(args);
            String backStateName = fragment.getClass().getName();

            boolean fragmentPopped = getActivity()
                    .getSupportFragmentManager().popBackStackImmediate(
                            backStateName, 0);

            if (!fragmentPopped) { // fragment not in back stack, create it.
                FragmentTransaction ft = getActivity()
                        .getSupportFragmentManager().beginTransaction();
                ft.replace(R.id.content_frame, fragment);
                ft.addToBackStack("TAG");
                ft.commit();
            }
            getActivity().getSupportFragmentManager().beginTransaction()
                    .replace(R.id.content_frame, fragment).commit();

Answer 1

您可以执行此操作

 private void showFragment() {

    final Myfragment fragment = new MyFragment();
    final FragmentTransaction transaction =
    getSupportFragmentManager().beginTransaction();
    transaction.replace(R.id.fragment, fragment, TAG_FRAGMENT);
    transaction.addToBackStack(null); 
    transaction.commit(); 
    }

@覆盖

   public void onBackPressed() {
   final Myfragment fragment = (Myfragment)getSupportFragmentManager().findFragmentByTag(TAG_FRAGMENT);

   if (fragment.allowBackPressed())  {
      super.onBackPressed(); 
   }

Answer 2

这可能不是你的问题，但它是我的：我过度骑着onSaveInstanceState（）而忘了打电话给超级。按下“后退”后，这会产生一个空白片段，几乎可以肯定，因为super.onSaveInstanceState（）是片段堆栈保存的地方。

后面堆栈片段空白onbackpressed

2 个答案: