private void initBGALayout() {
  // 为BGARefreshLayout 设置代理
  bgaRefreshLayout.setDelegate(this);
  // 设置下拉刷新和上拉加载更多的风格   参数1：应用程序上下文，参数2：是否具有上拉加载更多功能

  BGANormalRefreshViewHolder refreshViewHolder =
      new BGANormalRefreshViewHolder(getContext(), true);
  refreshViewHolder.setLoadingMoreText("加载更多");
  refreshViewHolder.setLoadMoreBackgroundColorRes(R.color.white);
  refreshViewHolder.setRefreshViewBackgroundColorRes(R.color.white);
  bgaRefreshLayout.setRefreshViewHolder(refreshViewHolder);
}

@Override
  public void onBGARefreshLayoutBeginRefreshing(BGARefreshLayout refreshLayout) {
  //执行下拉刷新操作
  }

  @Override
  public boolean onBGARefreshLayoutBeginLoadingMore(BGARefreshLayout refreshLayout) {
    //执行加载更多操作，返回false代表不支持加载更多
    return false;
  }

public interface JuheApi {
  @GET
  Observable<NewsBean> getNews(@Url String url);

  @GET
  Observable<FunnyBean> getFunny(@Url String url);

  @GET
  Observable<JokeBean> getJoke(@Url String url);

  @GET
  Observable<HistoryBean> getTodayInHistory(@Url String url);

  @GET
  Observable<QueryNewsBean> getQueryNews(@Url String url);
}

public class Retrofitance {
  public static final String BASE_URL = "http://gank.io/api/";

  private static final int DEFAULT_TIMEOUT = 5;

  private Retrofit retrofit;
  private JuheApi mJuheApi;
  private OkHttpClient mOkHttpClient;

  //构造方法私有
  private Retrofitance() {
    //手动创建一个OkHttpClient并设置超时时间
    OkHttpClient.Builder httpClientBuilder = new OkHttpClient.Builder();
    httpClientBuilder.connectTimeout(DEFAULT_TIMEOUT, TimeUnit.SECONDS);
    mOkHttpClient = httpClientBuilder.build();

    retrofit = new Retrofit.Builder().client(mOkHttpClient)
        .addConverterFactory(GsonConverterFactory.create())
        .addCallAdapterFactory(RxJava2CallAdapterFactory.create())
        .baseUrl(BASE_URL)
        .build();

    mJuheApi = retrofit.create(JuheApi.class);
  }

  //获取单例
  public static Retrofitance getInstance() {
    return SingletonHolder.INSTANCE;
  }

  /**
   * 根据类型获取新闻信息
   */
  public void getNews(Observer<NewsBean> subscriber, String type) {
    String URL = "";
    commonOp(mJuheApi.getNews(URL),subscriber);
  }

  /**
   * 获取趣图信息
   */
  public void getFunny(Observer<FunnyBean> subscriber, int pagenum) {
    String URL ="";
    commonOp(mJuheApi.getFunny(URL), subscriber);
  }

  /**
   * 获取历史上的今天
   */
  public void getHistory(Observer<HistoryBean> subscriber) {
    Calendar now = Calendar.getInstance();
    String URL = "";
    commonOp(mJuheApi.getTodayInHistory(URL),subscriber);
  }

  /**
   * 获取笑话大全
   */
  public void getJoke(Observer<JokeBean> subscriber, int pagenum) {
    String URL ="";
    commonOp(mJuheApi.getJoke(URL), subscriber);
  }


  public void getQueryNews(Observer<QueryNewsBean> subscriber, String keyword) {
    String URL = "";
    commonOp(mJuheApi.getQueryNews(URL), subscriber);
  }

  private void commonOp(Observable observable, Observer subscriber) {
    observable.subscribeOn(Schedulers.io())
        .unsubscribeOn(Schedulers.io())
        .observeOn(AndroidSchedulers.mainThread())
        .subscribe(subscriber);
  }
  //在访问HttpMethods时创建单例
  private static class SingletonHolder {
    private static final Retrofitance INSTANCE = new Retrofitance();
  }
}

public void getContent(int pagenum) {
  Observer<FunnyBean> observer = new Observer<FunnyBean>() {
    @Override
    public void onComplete() {
      endLoading();
    }

    @Override
    public void onError(Throwable e) {
      e.printStackTrace();
      endLoading();
      onNetworkError();
    }

    @Override
    public void onSubscribe(Disposable d) {

    }

    @Override
    public void onNext(FunnyBean funnyBean) {
      if (bgaRefreshLayout.isLoadingMore()) {
      } else {
        mVisitableList.clear();
      }
      if (funnyBean.getResult() == null || funnyBean.getResult().getData() == null
          || funnyBean.getResult().getData().size() == 0) {
        onDataEmpty();
      } else {
        mVisitableList.addAll(funnyBean.getResult().getData());
      }
      mMultiRecyclerAdapter.setData(mVisitableList);
    }
  };
  Retrofitance.getInstance().getFunny(observer, pagenum);
}

@BindView(R.id.tl_web)
Toolbar tlWeb;
@BindView(R.id.wv_content)
WebView wvContent;
@BindView(R.id.activity_web)
LinearLayout activityWeb;
@BindView(R.id.progressbar)
ProgressBar progressbar;

....
ButterKnife.bind(this);

Glide.with(itemView.getContext()).load(pic1path).placeholder(R.mipmap.empty_data).into(imageView);

compile 'com.squareup.retrofit2:converter-gson:2.1.0'
retrofit = new Retrofit.Builder().client(mOkHttpClient)
        /*This is the key*/ 
        .addConverterFactory(GsonConverterFactory.create())     .addCallAdapterFactory(RxJava2CallAdapterFactory.create())
        .baseUrl(BASE_URL)
        .build();

switch (i) {
  case 0:
    textView.setText("资讯");
    imageView.setImageResource(R.drawable.news);
    tabHost.addTab(tabHost.newTabSpec("1").setIndicator(view).setContent(
        R.id.frag_news));
    break;
  case 1:
    textView.setText("笑话");
    imageView.setImageResource(R.drawable.joke);
    tabHost.addTab(tabHost.newTabSpec("2").setIndicator(view).setContent(
        R.id.frag_joke));
    break;
  case 2:
    textView.setText("趣图");
    imageView.setImageResource(R.drawable.funny);
    tabHost.addTab(tabHost.newTabSpec("3").setIndicator(view).setContent(
        R.id.frag_funny));
    break;
  case 3:
    textView.setText("历史");
    imageView.setImageResource(R.drawable.history);
    tabHost.addTab(tabHost.newTabSpec("4").setIndicator(view).setContent(
        R.id.frag_history));
    break;
  default:
    break;
}

<android.support.v7.widget.Toolbar
  android:id="@+id/toolbar_search"
  android:layout_width="match_parent"
  android:layout_height="40dp"
  android:fitsSystemWindows="true"
  android:background="@color/colorToolbar">

  <LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <EditText
      android:id="@+id/et_search"
      android:layout_width="0dp"
      android:layout_height="match_parent"
      android:layout_marginBottom="8dp"
      android:layout_marginTop="8dp"
      android:layout_weight="6"
      android:background="@drawable/search_edittext_bg"
      android:padding="2dp"
      android:textColor="@color/colorBlack"
      android:textSize="12sp"/>

    <Button
      android:id="@+id/bt_search"
      android:layout_width="0dp"
      android:layout_height="match_parent"
      android:layout_weight="2"
      android:clickable="false"
      android:gravity="center"
      android:text="搜索"
      android:background="@color/colorToolbar"
      android:textColor="@color/colorToolbar"
      android:textSize="14sp"/>
  </LinearLayout>
</android.support.v7.widget.Toolbar>