scrollview react native code example

Example 1: how to detect onend reach of scrollview in react native

import React from 'react';
import {ScrollView, Text} from 'react-native';

const isCloseToBottom = ({layoutMeasurement, contentOffset, contentSize}) => {
  const paddingToBottom = 20;
  return layoutMeasurement.height + contentOffset.y >=
    contentSize.height - paddingToBottom;
};

const MyCoolScrollViewComponent = ({enableSomeButton}) => (
  <ScrollView
    onScroll={({nativeEvent}) => {
      if (isCloseToBottom(nativeEvent)) {
        enableSomeButton();
      }
    }}
    scrollEventThrottle={400}
  >
    <Text>Here is very long lorem ipsum or something...</Text>
  </ScrollView>
);

export default MyCoolScrollViewComponent;

Example 2: react native scrollview

import React from 'react';
import { StyleSheet, Text, ScrollView } from 'react-native';

export default function App() {
  return (
      <ScrollView style={styles.scrollView}>
        <Text style={styles.text}>
          Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do
          eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad
          minim veniam, quis nostrud exercitation ullamco laboris nisi ut
          aliquip ex ea commodo consequat. Duis aute irure dolor in
          reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla
          pariatur. Excepteur sint occaecat cupidatat non proident, sunt in
          culpa qui officia deserunt mollit anim id est laborum.
        </Text>
      </ScrollView>
  );
}

const styles = StyleSheet.create({
  scrollView: {
    backgroundColor: 'gray',
    marginHorizontal: 20,
  },
  text: {
    fontSize: 42,
  },
});

Example 3: react native scroll to

import React, { useRef } from 'react';
import { ScrollView, View, Button } from 'react-native';

export default function scrollTo() {
  	const scrollRef = useRef();
  
  	const handleClick = number => {
    	scrollRef.current.ScrollTo({
          y: (100 * number),
          animated: true,
    };
  
	return (
      <ScrollView ref={scrollRef} >
      	<View style={{height: '100px'}}>
      		<Button onPress={() => handleClick(1) title="1"/>
		</View>
		<View style={{height: '100px'}}>
      		<Button onPress={() => handleClick(2) title="2"/>
		</View>
		<View style={{height: '100px'}}>
      		<Button onPress={() => handleClick(3) title="3"/>
		</View>
		<View style={{height: '100px'}}>
      		<Button onPress={() => handleClick(4) title="4"/>
		</View>
		<View style={{height: '100px'}}>
      		<Button onPress={() => handleClick(5) title="5"/>
		</View>
      </ScrollView>
    );
}

Example 4: scrollview not working react-native

<View style={{flex:1}}>