我对导航器有问题...我有2个场景,主场景包含一个listView,第二个场景包含一个选择列表,该列表使我能够过滤列表视图的元素主要场景...问题是,当我从第二个场景返回时,列表视图的过滤元素未绘制...行显示了,但它们是空的
我知道它们之所以会显示,是因为我已经用不同的颜色对行进行了样式,并且颜色正确显示,我是否必须以某种方式强制ListView组件的渲染?如果是,我应该怎么做?
这是代码的某些部分(我已删除了无关的部分):
class App extends Component {
renderScene(route, navigator) {
switch (route.id) {
case 'Main':
return (<Main navigator={navigator} />);
case 'FilterByBrand':
return (<FilterByBrand navigator={navigator} brands={route.brands} callback={route.callback}/>);
}
}
render () {
return (
<Navigator
initialRoute={{id: 'Main'}}
renderScene={this.renderScene}
/>
);
}
}
-
class Main extends Component {
// code removed (irrelevant)
updateBrands(brands) {
var filter = {};
// code to generate filter to be used not shown, is working ok
this.setState({ brandFilter: filter });
}
render () {
return (
<Container>
<Header>
<Button>
<Icon name='md-pricetags'
onPress={()=>this.props.navigator.push({
id: 'FilterByBrand',
brands: this.state.brands,
callback: this.updateBrands}
)}
/>
</Button>
</Header>
<Content>
<ProdList
item={this.state.items}
brandFilter={this.state.brandFilter}
/>
</Content>
</Container>
);
}
}
-
class ProdList extends Component {
constructor(props) {
super(props);
this.dataSource = new ListView.DataSource({rowHasChanged: (r1, r2) => r1 !== r2});
this._filter = this._filter.bind(this);
this._genRow = this._genRow.bind(this);
}
_genRow(item) {
// code not shown (irrelevant)
}
_filter() {
let output = this.props.items;
// filtering code not shown, working ok
return output;
}
render() {
var dataSource = this.dataSource.cloneWithRows(this._filter());
return (
<ListView
style={styles.container}
dataSource={dataSource}
renderRow={this._genRow}
enableEmptySections={true}
/>
);
}
}
-
class FilterByBrand extends Component {
selectBrand(id) {
brands = // save here the selected brands
// callback
this.props.callback(brands);
this.setState({brands: brands});
}
render () {
return (
<Container>
<Header>
<Button transparent onPress={()=>this.props.navigator.pop()}>
<Icon name='ios-arrow-back' />
</Button>
<Title>Select brand(s)</Title>
</Header>
<Content>
<List
dataArray={this.state.brands}
renderRow={ (brand) =>
<ListItem onPress={() => this.selectBrand(brand.id)}>
<Text>{brand.name}</Text>
</ListItem>
}
/>
</Content>
</Container>
);
}
}
可能是您忘记添加参考
var navigator;
class App extends Component {
renderScene(route, navigator) {
switch (route.id) {
case 'Main':
return (<Main navigator={navigator} />);
case 'FilterByBrand':
return (<FilterByBrand navigator={navigator} brands={route.brands} callback={route.callback}/>);
}
}
render () {
return (
<Navigator
ref={(nav) => { navigator = nav; }}
initialRoute={{id: 'Main'}}
renderScene={this.renderScene}
/>
);
}
}