react-native/docs/UsingAListView.md
Gabriel Weyer c12681c214 Fix warning on SectionList's tutorial
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I wanted to fix issue #16231 - the warning is not displayed anymore:

![image](https://user-images.githubusercontent.com/2101647/31268083-7e2e0ddc-aac6-11e7-966b-b1e9ffa6cfa8.png)
Closes https://github.com/facebook/react-native/pull/16232

Differential Revision: D6005386

Pulled By: hramos

fbshipit-source-id: 33961ee7cd708c424c2665a38dc5e733f1ea2204
2017-10-07 16:40:43 -07:00

3.6 KiB

id title layout category permalink next previous
using-a-listview Using List Views docs The Basics docs/using-a-listview.html network using-a-scrollview

React Native provides a suite of components for presenting lists of data. Generally, you'll want to use either FlatList or SectionList.

The FlatList component displays a scrolling list of changing, but similarly structured, data. FlatList works well for long lists of data, where the number of items might change over time. Unlike the more generic ScrollView, the FlatList only renders elements that are currently showing on the screen, not all the elements at once.

The FlatList component requires two props: data and renderItem. data is the source of information for the list. renderItem takes one item from the source and returns a formatted component to render.

This example creates a simple FlatList of hardcoded data. Each item in the data props is rendered as a Text component. The FlatListBasics component then renders the FlatList and all Text components.

import React, { Component } from 'react';
import { AppRegistry, FlatList, StyleSheet, Text, View } from 'react-native';

export default class FlatListBasics extends Component {
  render() {
    return (
      <View style={styles.container}>
        <FlatList
          data={[
            {key: 'Devin'},
            {key: 'Jackson'},
            {key: 'James'},
            {key: 'Joel'},
            {key: 'John'},
            {key: 'Jillian'},
            {key: 'Jimmy'},
            {key: 'Julie'},
          ]}
          renderItem={({item}) => <Text style={styles.item}>{item.key}</Text>}
        />
      </View>
    );
  }
}

const styles = StyleSheet.create({
  container: {
   flex: 1,
   paddingTop: 22
  },
  item: {
    padding: 10,
    fontSize: 18,
    height: 44,
  },
})

// skip this line if using Create React Native App
AppRegistry.registerComponent('AwesomeProject', () => FlatListBasics);

If you want to render a set of data broken into logical sections, maybe with section headers, similar to UITableViews on iOS, then a SectionList is the way to go.

import React, { Component } from 'react';
import { AppRegistry, SectionList, StyleSheet, Text, View } from 'react-native';

export default class SectionListBasics extends Component {
  render() {
    return (
      <View style={styles.container}>
        <SectionList
          sections={[
            {title: 'D', data: ['Devin']},
            {title: 'J', data: ['Jackson', 'James', 'Jillian', 'Jimmy', 'Joel', 'John', 'Julie']},
          ]}
          renderItem={({item}) => <Text style={styles.item}>{item}</Text>}
          renderSectionHeader={({section}) => <Text style={styles.sectionHeader}>{section.title}</Text>}
          keyExtractor={(item, index) => index}
        />
      </View>
    );
  }
}

const styles = StyleSheet.create({
  container: {
   flex: 1,
   paddingTop: 22
  },
  sectionHeader: {
    paddingTop: 2,
    paddingLeft: 10,
    paddingRight: 10,
    paddingBottom: 2,
    fontSize: 14,
    fontWeight: 'bold',
    backgroundColor: 'rgba(247,247,247,1.0)',
  },
  item: {
    padding: 10,
    fontSize: 18,
    height: 44,
  },
})

// skip this line if using Create React Native App
AppRegistry.registerComponent('AwesomeProject', () => SectionListBasics);

One of the most common uses for a list view is displaying data that you fetch from a server. To do that, you will need to learn about networking in React Native.