FixedFragmentStatePagerAdapter.java

/*
 * Created by LuaView.
 * Copyright (c) 2017, Alibaba Group. All rights reserved.
 *
 * This source code is licensed under the MIT.
 * For the full copyright and license information,please view the LICENSE file in the root directory of this source tree.
 */

package com.taobao.luaview.view.adapter;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentStatePagerAdapter;
import android.util.Log;
import android.view.ViewGroup;

import java.lang.reflect.Field;

/**
 * 解决bug
 * android.os.BadParcelableException: ClassNotFoundException when unmarshalling: android.support.v4.app.FragmentManagerState
 * http://stackoverflow.com/questions/11381470/classnotfoundexception-when-unmarshalling-android-support-v4-view-viewpagersav
 * @author song
 */
public abstract class FixedFragmentStatePagerAdapter extends FragmentStatePagerAdapter {

    public FixedFragmentStatePagerAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Object instantiateItem(ViewGroup container, int position) {
        final Object fragment = super.instantiateItem(container, position);
        try {
            final Field saveFragmentStateField = Fragment.class.getDeclaredField("mSavedFragmentState");
            saveFragmentStateField.setAccessible(true);
            final Bundle savedFragmentState = (Bundle) saveFragmentStateField.get(fragment);
            if (savedFragmentState != null) {
                savedFragmentState.setClassLoader(Fragment.class.getClassLoader());
            }
        } catch (Exception e) {
            Log.w("FragmentPagerAdapter", "Could not get mSavedFragmentState field: " + e);
        }
        return fragment;
    }
}