react-native/docs/UsingAListView.md
Kevin Lacker bfb4c054f4 Make "The Basics" flow like a linear tutorial
Summary: Closes https://github.com/facebook/react-native/pull/8429

Differential Revision: D3487369

Pulled By: lacker

fbshipit-source-id: 59b32f2a2a67370192c91dc43da3d4b76a43b810
2016-06-26 12:43:25 -07:00

2.1 KiB

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using-a-listview Using a ListView docs The Basics docs/using-a-listview.html network

The ListView component displays a vertically scrolling list of changing, but similarly structured, data.

ListView works well for long lists of data, where the number of items might change over time. Unlike the more generic ScrollView, the ListView only renders elements that are currently showing on the screen, not all the elements at once.

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

This example creates a simple ListView of hardcoded data. It first initializes the dataSource that will be used to populate the ListView. Each item in the dataSource is then rendered as a Text component. Finally it renders the ListView and all Text components.

A rowHasChanged function is required to use ListView. Here we just say a row has changed if the row we are on is not the same as the previous row.

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

class ListViewBasics extends Component {
  // Initialize the hardcoded data
  constructor(props) {
    super(props);
    const ds = new ListView.DataSource({rowHasChanged: (r1, r2) => r1 !== r2});
    this.state = {
      dataSource: ds.cloneWithRows([
        'John', 'Joel', 'James', 'Jimmy', 'Jackson', 'Jillian', 'Julie', 'Devin'
      ])
    };
  }
  render() {
    return (
      <View style={{paddingTop: 22}}>
        <ListView
          dataSource={this.state.dataSource}
          renderRow={(rowData) => <Text>{rowData}</Text>}
        />
      </View>
    );
  }
}

// App registration and rendering
AppRegistry.registerComponent('AwesomeProject', () => ListViewBasics);

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