React Native - Switch

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In this chapter, we will explain the Switch component in a couple of steps.

Step 1: Create File

We will use the HomeContainer component for logic, but we need to create the presentational component.

Let us now create a new file: SwitchExample.js.

Step 2: Logic

We are passing value from the state and functions for toggling switch items to SwitchExample component. Toggle functions will be used for updating the state.

App.js

import React, { Component } from 'react'
import { View } from 'react-native'
import SwitchExample from './switch_example.js'

export default class HomeContainer extends Component {
   constructor() {
      super();
      this.state = {
         switch1Value: false,
      }
   }
   toggleSwitch1 = (value) => {
      this.setState({switch1Value: value})
      console.log('Switch 1 is: ' + value)
   }
   render() {
      return (
         <View>
            <SwitchExample
            toggleSwitch1 = {this.toggleSwitch1}
            switch1Value = {this.state.switch1Value}/>
         </View>
      );
   }
}

Step 3: Presentation

Switch component takes two props. The onValueChange prop will trigger our toggle functions after a user presses the switch. The value prop is bound to the state of the HomeContainer component.

switch_example.js

import React, { Component } from 'react'
import { View, Switch, StyleSheet }

from 'react-native'

export default SwitchExample = (props) => {
   return (
      <View style = {styles.container}>
         <Switch
         onValueChange = {props.toggleSwitch1}
         value = {props.switch1Value}/>
      </View>
   )
}
const styles = StyleSheet.create ({
   container: {
      flex: 1,
      alignItems: 'center',
      marginTop: 100
   }
})

If we press the switch, the state will be updated. You can check values in the console.

Output