RN请求豆瓣数据

/*
工具类
*/
import React, { Component} from 'react';
import {
  AppRegistry,
  StyleSheet,
  Text,
  View,
  Dimensions, //用于获取设备屏幕的宽高
  ActivityIndicator
} from 'react-native';
var Util = {
  //屏幕尺寸
  windowSize: {
    width: Dimensions.get("window").width,
    height:Dimensions.get("window").height
  },
  getRequest: function(url,successCallback, failCallback) {
    fetch(url)
    .then((response) => response.json())
    .then((responseData) => successCallback(responseData))
    .catch((error) => failCallback(error));
  },
// loading效果
  loading:<ActivityIndicator style={{marginTop: 200}}/>
}
module.exports = Util;

  getData: function() {
    this.setState({
      show: false
    });
    // 请求数据
    var that = this;
    //https://api.douban.com/v2/book/search?count=20&q=react
    var url = ServiceURL.book_search + "?count=20&q=" + this.state.keywords;
    Util.getRequest(url,function(data){
      // 请求成功回调
      if (!data.books || data.books.length == 0) {
        return alert("未查询到相关书籍")
      }
      var ds = new ListView.DataSource({
        rowHasChanged: (oldRow, newRow) => oldRow!==newRow
      });
      that.setState({
        show: true,
        dataSource: ds.cloneWithRows(data.books)
      });
    }, function(error){
      // 请求失败回调
      alert(error);
    })
  },