react-native/docs/UsingAListView.md
Hector Ramos b1ecb84c97 Standardize on using AwesomeProject for AppRegistry calls.
Summary:
We've noticed that many newcomers paste sample code straight into a project created using `react-native init AwesomeProject`, but the sample code assumes the user is creating a new project for each example. This PR makes it so that these samples can be pasted into the same project from the Getting Started.
Closes https://github.com/facebook/react-native/pull/14264

Differential Revision: D5149746

Pulled By: hramos

fbshipit-source-id: cae95ab5b7baf64ddd9fe12d342ad05f785bb381
2017-05-30 14:20:42 -07:00

2.2 KiB

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

The ListView component displays a 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';

export default 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={{flex: 1, paddingTop: 22}}>
        <ListView
          dataSource={this.state.dataSource}
          renderRow={(rowData) => <Text>{rowData}</Text>}
        />
      </View>
    );
  }
}

// skip this line if using Create React Native App
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.