在取向改变后保留当前可见碎片

Question

if (savedInstanceState == null) {
            mFragment = new Fragment1();
            showFragment(mFragment, FRAGMENT1_TAG);
        } else {
            String tag = savedInstanceState.getString(CURRENT_FRAGMENT_TAG);
            mFragment = mFragmentManager.findFragmentByTag(tag);

            if (mFragment != null)
                mFragmentManager.beginTransaction().replace(R.id.content_frame, mFragment, tag).commit();
            else
                Toast.makeText(getBaseContext(), "Something went wrong, please restart application", Toast.LENGTH_SHORT).show();
        }

String fragmentTag = mFragmentManager.findFragmentById(R.id.content_frame).getTag();
        dataOut.putString(CURRENT_FRAGMENT_TAG, fragmentTag);

 public static void showFragment(Fragment fragment, String tag) {
        mFragmentTag = tag;

        FragmentTransaction fragmentTransaction = mFragmentManager.beginTransaction();
        fragmentTransaction.replace(R.id.content_frame, fragment, mFragmentTag);
        fragmentTransaction.addToBackStack(null);
        fragmentTransaction.commit();
    }

Answer 1

在包中保留您的片段的类的名称。

然后使用static方法实例化，用类的名称重新创建片段。

String name = savedInstanceState.getString(CURRENT_FRAGMENT_TAG);
Fragment fragment = Fragment.instantiate (Activity.this, "com.example." + name);

该方法需要全名（包括包）。