How to add styling or css to your app using reactnative?

Styling your app can be done as follows −

• Using Stylesheet component
• Using Inline styles

Using Stylesheet component

React native Stylesheet component comes very handy and neat when you want to apply styling to your app. To work with Stylesheet component first import it as shown below −

import { StyleSheet } from 'react-native';

You can create the style using Stylesheet component as follows −

const styles = StyleSheet.create({
   container: {
      flex: 1,
      marginTop: StatusBar.currentHeight || 0,
   },
   item: {
      margin: 10,
      padding: 20,
      marginVertical: 8,
      marginHorizontal: 16,
   }
});

The above style can be used as follows inside your code −

<View style={styles.container}></View>

Here is an example that makes use of Stylesheet for display of FlatList component −

Example 1

import React from "react";
import { FlatList , Text, View, StyleSheet, StatusBar } from "react-native";
export default class App extends React.Component {
   constructor() {
      super();
      this.state = {
         data: [
            { name: "Javascript Frameworks", isTitle: true },
            { name: "Angular", isTitle: false },
            { name: "ReactJS", isTitle: false },
            { name: "VueJS", isTitle: false },
            { name: "ReactNative", isTitle: false },
            { name: "PHP Frameworks", isTitle: true },
            { name: "Laravel", isTitle: false },
            { name: "CodeIgniter", isTitle: false },
            { name: "CakePHP", isTitle: false },
            { name: "Symfony", isTitle: false }
         ],
         stickyHeaderIndices: []
      };
   }
   renderItem = ({ item }) => {
      return (
         <View style={styles.item}>
            <Text style={{ fontWeight: (item.isTitle) ? "bold" : "", color: (item.isTitle) ? "red" : "gray"}} >
               {item.name}
            </Text>
         </View>
      );
   };
   render() {
      return (
         <View style={styles.container}>
            <FlatList
               data={this.state.data}
               renderItem={this.renderItem}
               keyExtractor={item => item.name}
               stickyHeaderIndices={this.state.stickyHeaderIndices}
            />
         </View>
      );
   }
}
const styles = StyleSheet.create({
   container: {
      flex: 1,
      marginTop: StatusBar.currentHeight || 0,
   },
   item: {
      margin: 10,
      padding: 20,
      marginVertical: 8,
      marginHorizontal: 16,
   }
});

Output

Using Inline styles

You can use the style property to add the styles inline. However, this is not the best practice because it can be hard to read the code. Here is a working example on how to use inline style inside reactnative component

Example 2

export default App;

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

const App = () => {
   return (
      <View style={{flex :1, justifyContent: 'center', margin: 15 }}>
         <Button
            title="Click Me"
            color="#9C27B0"
            onPress={() => Alert.alert('Testing Button for React Native ')}
         />
      </View>
   );
}

Output