react-native-swiper方法scrollBy

Question

如果单击索引0，则该方法不起作用。如果我点击索引0，1和2将停止工作。如果我在1或2上单击2次，则滑块将转到所需的幻灯片。但零指数根本不起作用。请告诉我，可能的问题是什么？

   <Swiper
        onMomentumScrollEnd={(e, state, context) => this.setState({index: 
        state.index})}
        ref={(swiper) => {this.swiper = swiper;}}
        showsButtons={false}
        width={500}
        height={500}
        showsPagination={false}
        index={0}
        loop={true} >
        <View>
            <Text>One</Text>
        </View>
        <View>
            <Text>Two</Text>
        </View>
        <View>
            <Text>Three</Text>
        </View>
    </Swiper>
    <Text onPress={()=>{this.swiper.scrollBy(0, true)}}>One</Text>
    <Text onPress={()=>{this.swiper.scrollBy(1, true)}}>Two</Text>
    <Text onPress={()=>{this.swiper.scrollBy(2, true)}}>Three</Text>

Answer 1

我这样做的方法：

onClickScroll(index){
    let currentIndex = this.state.index;

    if(currentIndex !== index) {
        let resultSlide = undefined;
        let countSlides = this.state.itineraryDaysListItem.length;

        if(index > currentIndex && index !== countSlides)
        {
            resultSlide = index - currentIndex;
            this.swiper.scrollBy(resultSlide, true);
        }
        else if(index>currentIndex && index === countSlides)
        {
            resultSlide = currentIndex+1;
            this.swiper.scrollBy(resultSlide, true);
        }
        else if(index < currentIndex && index !== 0){
            resultSlide = (currentIndex - index) * (-1);
            this.swiper.scrollBy(resultSlide, true);
        }
        else if(index < currentIndex && index === 0){
            resultSlide = currentIndex * (-1);
            this.swiper.scrollBy(resultSlide, true);
        }
    }
}               

Answer 2

下面的实现适用于我

    'use strict'
import React, { Component } from 'react';
import {
  AppRegistry,
  StyleSheet,
  Text,
  View
} from 'react-native';

import Swiper from 'react-native-swiper';

var styles = StyleSheet.create({
  wrapper: {
  },
  slide1: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center',
    backgroundColor: '#9DD6EB',
  },
  slide2: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center',
    backgroundColor: '#97CAE5',
  },
  slide3: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center',
    backgroundColor: '#92BBD9',
  },
  text: {
    color: '#fff',
    fontSize: 30,
    fontWeight: 'bold',
  }
})
export default class swiper  extends Component{
  constructor (props) {
    super(props)
    this.swiperRef = swiper => this.swiper = swiper
    this.scrollHandler = page => {
      console.log ('Page ',page,this.swiper)
      this.swiper && this.swiper.scrollBy(page, true)
    }
  }
  render (){
    return (
      <Swiper
        ref={ this.swiperRef }
        showsButtons={false}
        width={500}
        height={500}
        showsPagination={false}
        index={0}
        loop={true} >
        <View style={ styles.slide1 }>
            <Text style={ styles.text } onPress={()=>{console.log('Page 0'); this.swiper.scrollBy(1, true)}}>One</Text>
        </View>
        <View style={ styles.slide2 }>
             <Text style={ styles.text } onPress={()=>{console.log('Page 1'); this.swiper.scrollBy(1, true)}}>Two</Text>
        </View>
        <View style={ styles.slide3 } >
            <Text style={ styles.text } onPress={()=>{console.log('Page 2');this.swiper.scrollBy(2, true)}}>Three</Text>
        </View>
    </Swiper>
    )
  }
}


AppRegistry.registerComponent('myproject', () => swiper);

Answer 3

对于在2019年阅读这篇文章并使用函数组件/挂钩编写的任何人来说。

import React, { useRef } from 'react'
import Swiper from 'react-native-swiper'

const YourCoolComponent = () => {
  const swiper = useRef(null)
  return (
    <Swiper ref={swiper}>
      <View>
        <Text>Page 1</Text>
        <Button onPress={() => swiper.current.scrollBy(1)}>Forward</Button>
      </View>
      <View>
        <Text>Page 2</Text>
        <Button onPress={() => swiper.current.scrollBy(-1)}>Backward</Button>
      </View>
    </Swiper>
  )
}