我的App.js中有导航屏幕,其中一个屏幕呈现自定义标头为:
const DailyStack = createStackNavigator({
Dashboard,
SalesDashboard: {
screen : SalesDashboard,
navigationOptions:{
header: null,
}
},
StackNavSecond : {
screen: StackNavSecond,
navigationOptions : {
header : <CustomHeader />,
}
},....
然后在我的CustomHeader.js
文件中,我有一些状态数据:
class CustomHeader extends Component {
constructor(props) {
super(props)
this.state = {
title:'Regions',
subtitle:'',
oem: ''
}
}
async componentDidMount(){
let car_brand = await AsyncStorage.getItem('brand_name');
let main_oem = await AsyncStorage.getItem('oem_name');
await this.setState({
oem: main_oem,
subtitle: car_brand,
});
console.log(this.state.oem)
}
render() {
console.log(this.state.title)
const {title, subtitle, oem} = this.state;
return (
<View>
<CustomDropdown title={title} subtitle={subtitle} oem={oem} />
</View>
)
}
}
export default withNavigation(CustomHeader);
道具title
不会传递给子组件,该子组件将在另外两个屏幕中进一步渲染。
CustomDropdown.js
的代码是:
class CustomDropdown extends Component {
constructor(props) {
super(props)
this.state = {
title: '',
oem: '',
subtitle:''
};
}
componentDidMount(){
this.setState({
title:this.props.title,
subtitle: this.props.subtitle,
oem: this.props.oem,
});
console.log(this.state.title, this.state.oem, this.state.subtitle)
}
render() {
return (
<View style={{flexDirection:'row', justifyContent: 'space-between'}}>
.........
</View>
)
}
}
export default withNavigation(CustomDropdown);
当我控制台this.state.title
时,它会打印但subtitle
和oem
却没有值。我什至尝试将控制台语句放在callback()
的{{1}}中,但仍然没有oem和字幕显示道具。
请帮助解决此问题。
答案 0 :(得分:0)
当您不想交付组件时,可以使用withNavigation
。但是您的代码是深层嵌套的。
如果要这样使用,可以更改代码。
CustomHeader.js
class CustomHeader extends React.Component {
constructor(props) {
super(props)
this.state = {
title:'Regions',
subtitle:'',
oem: ''
}
}
async componentDidMount(){
let car_brand = await AsyncStorage.getItem('brand_name');
let main_oem = await AsyncStorage.getItem('oem_name');
this.setState({
oem: main_oem,
subtitle: car_brand,
});
console.log(this.state.oem)
}
render() {
console.log(this.state.title)
const {title, subtitle, oem} = this.state;
return (
<View>
<CustomDropdown title={title} subtitle={subtitle} oem={oem} />
</View>
)
}
}
export default withNavigation(CustomHeader);
CustomDropdown.js
class CustomDropdown extends React.Component {
constructor(props) {
super(props);
this.state = {
title: props.title,
oem: props.oem,
subtitle: props.subtitle
};
}
componentDidMount(){
console.log(this.state.title, this.state.oem, this.state.subtitle)
}
render() {
return (
<View style={{flexDirection:'row', justifyContent: 'space-between'}}>
.........
</View>
)
}
}
export default CustomDropdown;