ReactNative：FlatList onRefresh not called on pull up.

Current Behavior:

我试图通过打开视图来更新从服务器获取的列表.当我这样做时，onRefresh不会启动.

我已经在setState函数的回调中设置了GET请求，但这似乎没有任何作用.

Expected Behavior:

打开视图调用onRefresh函数.

代码:

...
  constructor(props) {
    super(props);
    this.state = {
      stories: [],
      isFetching: false,
    };
  }
  componentDidMount() { this.fetchData() }
  onRefresh() {
    this.setState({ isFetching: true }, function() { this.fetchData() });
  }
  fetchData() {
    var that = this;
    axios.get('http://192.168.0.13:3000/api/story/get/by/geo')
      .then((res) => {
        that.setState({ stories: res.data, isFetching: false });
        that.props.dispatch(StoryActions.setStories(res.data))
      })
  }
  render() {
    return (
      <ScrollView>
        <FlatList
          onRefresh={() => this.onRefresh()}
          refreshing={this.state.isFetching}
          data={this.state.stories}
          keyExtractor={(item, index) => item.id}
          renderItem={({item}) => (<StoryFeed story={item} id={item.id} /> )}
          />
      </ScrollView>
    )
  }

Version Information

react 本机:0.45.0

node :7.4.0