Question

我不确定为什么在我的数据更改时ListView没有更新。我已经将代码条带化，以便于阅读和创建一个rnplay：

我期望发生的是，用户点击列表项并切换行的布尔isCollapsed，使背景变为红色。实际发生的是数据源已更新但列表视图无法识别更改并且未呈现任何新内容。有什么想法吗？

'use strict';

var React = require('react-native');

var {
    ScrollView,
    Text,
    Image,
    StyleSheet,
    TouchableHighlight,
    AppRegistry,
    View,
    ListView,
} = React;

var styles = StyleSheet.create({
    container: {
        flex: 1,
        flexDirection: 'column',
        padding: 15,
    },
    red: {
        backgroundColor: "red",
    }
});

var foods = [
    {key: 'Almond Milk (Homemade)', details:''},
    {key: 'Club Soda', details:'', isCollapsed: true},
    {key: 'Coconut Milk/Cream', details:''},
    {key: 'Coconut Water', details:''},
    {key: 'Coffee/Espresso', details:'', isCollapsed: true},
    {key: 'Fruit Juice', details:''},
    {key: 'Kombucha', details:''},
    {key: 'Mineral Water', details:''},
    {key: 'Unsweetened Tea', details:''},
    {key: 'Water', details:''},
    {key: 'Fruit Juice', details:''},
    {key: 'Kombucha', details:''},
    {key: 'Mineral Water', details:''},
    {key: 'Unsweetened Tea', details:''},
    {key: 'Water', details:''},
    {key: 'Fruit Juice', details:''},
    {key: 'Kombucha', details:''},
    {key: 'Mineral Water', details:''},
    {key: 'Unsweetened Tea', details:''},
    {key: 'Water', details:''},
    {key: 'Fruit Juice', details:''},
    {key: 'Kombucha', details:''},
    {key: 'Mineral Water', details:''},
    {key: 'Unsweetened Tea', details:''},
    {key: 'Water', details:''},
    {key: 'Fruit Juice', details:''},
    {key: 'Kombucha', details:''},
    {key: 'Mineral Water', details:''},
    {key: 'Unsweetened Tea', details:''},
    {key: 'Water', details:''},
];

class SampleApp extends React.Component{
    constructor(props){
        super(props);
        var ds = new ListView.DataSource({
            rowHasChanged: (row1, row2) => row1 !== row2,
        });
        this.state = {
            dataSource: ds.cloneWithRows(foods),
        };
    }
    _renderRow(data, sectionID, rowID) {
                return (
                        <TouchableHighlight 
                            style={[
                                    styles.container,
                                    data.isCollapsed && styles.red]}
                onPress={()=>this.onCollapse(rowID)}>
                <Text>{data.key}</Text>
            </TouchableHighlight>
        );
    }
    onCollapse(rowID: number) {
        console.log("rowID", rowID);
        foods[rowID].isCollapsed = !foods[rowID].isCollapsed;
        this.setState({dataSource: this.state.dataSource.cloneWithRows(foods)});
    }
    render() {
        return(
            <ListView
                style={styles.subContainer}
                dataSource={this.state.dataSource}
                renderRow={this._renderRow.bind(this)}
                initialListSize={15}/>
        )
    }
};

AppRegistry.registerComponent('SampleApp', () => SampleApp);

Answer 1

这是指向工作版本的链接：

https://rnplay.org/apps/GWoFWg

这些是我需要修改它的更改：

constructor(props){
    super(props);
    var ds = new ListView.DataSource({
        rowHasChanged: (row1, row2) => row1 !== row2,
    });
    this.state = {
        dataSource: ds.cloneWithRows(foods),
        db: foods,
    };
}

和此：

onCollapse(rowID: number) {
    var newArray = this.state.db.slice();
    newArray[rowID] = {
        key: newArray[rowID].key,
        details: newArray[rowID].details,
        isCollapsed: newArray[rowID].isCollapsed == false ? true : false,
    };
    this.setState({
        dataSource: this.state.dataSource.cloneWithRows(newArray),
        db: newArray,
    });
}

Answer 2

看起来这将是您需要的解决方案 React-Native Updating List View DataSource

但我玩了一下它也无法让它发挥作用。 https://rnplay.org/apps/sk_ukQ

不确定它是否会有所帮助，但我尝试将此数组设置为空白并且能够清除整个列表... this.setState（{dataSource：this.state.dataSource.cloneWithRows（[]）}）;

我认为由于某种原因，它使用原始数组的缓存版本而不是更新的数组。只是不确定为什么。

React Native ListView不会更新数据更改

2 个答案: