<Swiper
   style={styles.wrapper}
   height={width*40/75}
   showsButtons={false}
   autoplay={true}
   paginationStyle={styles.paginationStyle}
   dotStyle={styles.dotStyle}
   activeDotStyle={styles.activeDotStyle}
>
    <Image source={require('../../img/1.jpg')} style={styles.bannerImg} />
    <Image source={require('../../img/2.jpg')} style={styles.bannerImg} />
    <Image source={require('../../img/3.jpg')} style={styles.bannerImg} />
    <Image source={require('../../img/4.jpg')} style={styles.bannerImg} />
    <Image source={require('../../img/3.jpg')} style={styles.bannerImg} />
</Swiper>

const styles = StyleSheet.create({
  container: {
    flex: 1,
    alignItems: 'center',
    backgroundColor: '#fff',
  },
  bannerImg: {
    height: width*40/75,
    width: width,
  },
  wrapper: {
    width: width,
  },
  paginationStyle: {
    bottom: 6,
  },
  dotStyle: {
    width: 22,
    height: 3,
    backgroundColor:'#fff',
    opacity: 0.4,
    borderRadius: 0,
  },
  activeDotStyle: {
    width: 22,
    height: 3,
    backgroundColor:'#fff',
    borderRadius: 0,
  },
});

if (this.state.swiperShow) {
  return (
   <Swiper >
     …………略
   </Swiper>
  )
} else {
  return (
   <View style={{ height: width*40/75 }}>
     <Image source={require('../../img/1.jpg')} style={styles.bannerImg} />
   </View>
  );
}