1、render部分

onScroll在滾動(dòng)的過(guò)程中，每幀最多調(diào)用一次此回調(diào)函數(shù)。調(diào)用的頻率可以用scrollEventThrottle屬性來(lái)控制，數(shù)字越大，跟蹤滾動(dòng)位置的代碼的準(zhǔn)確性就越高

  render() {
    return (
      <View style={styles.container}>
        {this.renderNavBar()}
        <ScrollView
          ref={view => {
            this.ScrollView = view;
          }}
          horizontal
          style={styles.wrapper}
          showsHorizontalScrollIndicator={false}
          pagingEnabled
          onMomentumScrollEnd={event => this.scrollEnd(event)}
        >
          <QuotationList data={marketStockReqData} />
          <QuotationList data={userStockReqData} />
        </ScrollView>
      </View>
    );
  }

2、scrollEnd計(jì)算offset偏移量

  scrollEnd = event => {
    const offsetX = event.nativeEvent.contentOffset.x;
    const currentPage = Math.floor(offsetX / screenW);
    this.setState({
      tabIndex: currentPage
    });
  };

3、點(diǎn)擊segement時(shí)滾動(dòng)到對(duì)應(yīng)offset

  onMarketStockTab = () => {
    this.ScrollView.scrollTo({ x: 0, y: 0, animated: true });
    this.setState({
      tabIndex: 0
    });
  };

  onUserStockTab = () => {
    this.ScrollView.scrollTo({ x: screenW, y: 0, animated: true });
    this.setState({
      tabIndex: 1
    });
  };