Implement pull to refresh FlatList

please help me out to implement pull to refresh on my app, I'm kinda new to react native, thanks. I don't know how to handle onRefresh and refreshing.

class HomeScreen extends Component {
  state = { refreshing: false }

  _renderItem = ({ item }) => <ImageGrid item={item} />

  _handleRefresh = () => {

  };

  render() {
    const { data } = this.props;
    if (data.loading) {
      return (
        <Root>
          <Loading size="large" />
        </Root>
      )
    }
 return (
   <Root>
     <HomeHeader />
     <FlatList
       contentContainerStyle={{ alignSelf: 'stretch' }}
       data={data.getPosts}
       keyExtractor={item => item._id}
       renderItem={this._renderItem}
       numColumns={3}
       refreshing={this.state.refreshing}
       onRefresh={this._handleRefresh}
     />
   </Root>
  );
 }
}

export default graphql(GET_POSTS_QUERY)(HomeScreen);

Set variable

this.state = { 
    isFetching: false,
}

Create Refresh function

onRefresh() {
    this.setState({isFetching: true,},() => {this.getApiData();});
}

And in last set onRefresh and refreshing in FlatList.

<FlatList
    data={ this.state.FlatListItems }
    onRefresh={() => this.onRefresh()}
    refreshing={this.state.isFetching}
/>

After fetching Data in function getApiData Make sure to set false isFetching.

this.setState({ isFetching: false })

You can also use refreshControl in Flatlist, ScrollView, and any other list component.

<FlatList
  contentContainerStyle={{ alignSelf: 'stretch' }}
  data={data.getPosts}
  keyExtractor={(item) => item._id}
  renderItem={this._renderItem}
  numColumns={3}
  refreshControl={
    <RefreshControl
      refreshing={this.state.refreshing}
      onRefresh={this._handleRefresh}
    />
  }
/>
    

// Sample code representing pull to refresh in flatlist. Modify accordingly.

import React, { Component } from 'react'
    import { Text, View,StyleSheet,FlatList,Dimensions,Image,TouchableHighlight } from 'react-native'

    export default class Home extends Component {

        constructor(props) 
        {
            super(props);
        this.state = {
            data : [],
            gender : "",
            isFetching: false,
        }
        }

    componentWillMount()
    {

        this.searchRandomUser()
    }

    onRefresh() {
        this.setState({ isFetching: true }, function() { this.searchRandomUser() });
     }

    searchRandomUser = async () =>
    {
       const RandomAPI = await fetch('https://randomuser.me/api/?results=20')
       const APIValue = await RandomAPI.json();
        const APIResults = APIValue.results
          console.log(APIResults[0].email);
          this.setState({
              data:APIResults,
              isFetching: false
          })

    }

      render() {
        return (
          <View style = {styles.container}>
     <TouchableHighlight
     onPressOut = {this.searchRandomUser}
         style = {{width:deviceWidth - 32, height:45,backgroundColor: 'green',justifyContent:"center",alignContent:"center"}}>
              <Text style = {{fontSize:22,color: 'white',fontWeight: 'bold',textAlign:"center"}}>Reload Data</Text>
         </TouchableHighlight>
     <FlatList
            data={this.state.data}
            onRefresh={() => this.onRefresh()}
          refreshing={this.state.isFetching}
            keyExtractor = { (item, index) => index.toString() }
            renderItem={({item}) =>
            <View style = {styles.ContainerView}>
            <View>
    <Image
    source={{uri : item.picture.large}}
    style = {{height:100,width:100,borderRadius: 50,marginLeft: 4}}
    resizeMode='contain'
    />
    </View>

    <View style = {{flexDirection: 'column',marginLeft:16,marginRight: 16,flexWrap:'wrap',alignSelf:"center",width: deviceWidth-160}}>
    <Text>Email Id : {item.email}</Text>

    <Text>Full Name : {this.state.gender} {item.name.first} {item.name.last}</Text>
    <Text>Date of birth : {item.dob.age}</Text>
    <Text>Phone number : {item.phone}</Text>

    </View>

    </View>
            }
            />
          </View>
        )
      }
    }
    const deviceWidth = Dimensions.get('window').width
    const deviceHeight = Dimensions.get('window').height
    const styles = StyleSheet.create({
        container: {
          flex: 1,
          alignItems: 'center',
          justifyContent: 'center',
          marginTop:22
        },
        ContainerView:
        {
            // backgroundColor:'grey',
            marginBottom:20,
            paddingVertical:10,
            backgroundColor: '#F5F5F5',

            borderBottomWidth:0.5,
            borderBottomColor:'grey',
            width: deviceWidth-40,
            marginLeft:20,
            marginRight:20,
            marginTop:20,
            flexDirection:'row'
        }
      });

const [refreshing, setRefreshing] = useState(false)
    
 <FlatList
     style={{ padding: 15 }}
     refreshControl={
         <RefreshControl 
             refreshing={refreshing} 
             onRefresh={_onRefresh}
             tintColor="#F8852D"/>
     }
     showsVerticalScrollIndicator={false}
     data={listData}
     renderItem={renderItem}
     item={(item, index) => index.toStirng()}
     onEndReachedThreshold={0.8}
     onEndReached={() => onEndReached()}
     ListFooterComponent={() => renderFooter()}
 /> 

_onRefresh Function

const _onRefresh = () => {
    console.log('_onRefresh')
    setRefreshing(true);
    getPosts();
};