@Override
    public Fragment getItem(int i) {
      Fragment fragment = null;
      switch (i) {
        case 0:
          mMainConversationTv.setTextColor(getResources().getColor(R.color.de_title_bg));
          // TODO
          if (mConversationFragment == null) {
            ConversationListFragment listFragment = ConversationListFragment.getInstance();
            listFragment.setAdapter(new ConversationListAdapterEx(RongContext.getInstance()));
            Uri uri =
                Uri.parse("rong://" + getApplicationInfo().packageName)
                    .buildUpon()
                    .appendPath("conversationlist")
                    .appendQueryParameter(
                        Conversation.ConversationType.PRIVATE.getName(), "false") // 设置私聊会话是否聚合显示
                    .appendQueryParameter(
                        Conversation.ConversationType.GROUP.getName(), "false") // 群组
                    .appendQueryParameter(
                        Conversation.ConversationType.DISCUSSION.getName(), "false") // 讨论组
                    .appendQueryParameter(
                        Conversation.ConversationType.PUBLIC_SERVICE.getName(), "false") // 公共服务号
                    .appendQueryParameter(
                        Conversation.ConversationType.SYSTEM.getName(), "false") // 系统
                    .build();
            listFragment.setUri(uri);
            fragment = listFragment;
          } else {
            fragment = mConversationFragment;
          }
          break;
        case 1:
          if (mGroupListFragment == null) {
            mGroupListFragment = new GroupListFragment();
          }

          fragment = mGroupListFragment;

          break;

        case 2:
          if (mChatroomFragment == null) {
            fragment = new ChatRoomListFragment();
          } else {
            fragment = mChatroomFragment;
          }
          break;
        case 3:
          if (mCustomerFragment == null) {
            fragment = new CustomerFragment();
          } else {
            fragment = mCustomerFragment;
          }
          break;
      }
      return fragment;
    }
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.rong_activity);

    ConversationListFragment fragment = new ConversationListFragment();
    Uri uri =
        Uri.parse("rong://" + getApplicationInfo().packageName)
            .buildUpon()
            .appendPath("conversationlist")
            .appendQueryParameter(
                Conversation.ConversationType.PRIVATE.getName(), "true") // 设置私聊会话是否聚合显示
            .appendQueryParameter(Conversation.ConversationType.GROUP.getName(), "true")
            .appendQueryParameter(Conversation.ConversationType.DISCUSSION.getName(), "false")
            .appendQueryParameter(Conversation.ConversationType.SYSTEM.getName(), "true")
            .build();
    fragment.setUri(uri);

    FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
    // xxx 为你要加载的 id
    transaction.add(R.id.rong_content, fragment);
    transaction.commit();
  }