使用IndicatorFragmentActivity添加子级Fragment时，在Activity中获取子级的方法

MainActivity

FragmentTransaction transaction=getSupportFragmentManager().beginTransaction();
        //这里的fragment就是父级Fragment，MyFragmentList继承了IndicatorFragmentActivity
        MyFragmentList fragment=new MyFragmentList();
        //添加父级Fragment
        transaction.add(R.id.id_ll_content,fragment).transaction.commit();
        //使用父级Fragment获取管理子级Fragment的管理器，并通过该管理器获取子级Fragment的集合
        List<Fragment>fragments=fragment.getChildFragmentManager().getFragments();
        //根据添加顺序，从集合中取出子级Fragment，转换成相应对象就可以啦
        FragmentOne fragmentOne=(FragmentOne)fragments.get(0);

MyFragmentList

/**
*在MyFragmentList中添加子级Fragment
*/
public class MyFragmentList extends IndicatorFragmentActivity {

    public static final int FRAGMENT_ONE = 0;
    public static final int FRAGMENT_TWO = 1;
    public static final int FRAGMENT_THREE = 2;
    @Override
    protected int supplyTabs(List<TabInfo> tabs) {
        tabs.add(new IndicatorFragmentActivity.TabInfo(FRAGMENT_ONE, "FragmentOne",FragmentOne.class));
            tabs.add(new IndicatorFragmentActivity.TabInfo(FRAGMENT_TWO, "FragmentTwo",FragmentTwo.class));
            tabs.add(new IndicatorFragmentActivity.TabInfo(FRAGMENT_THREE, "FragmentThree",FragmentThree.class));
        return FRAGMENT_ONE;

    }
}