Javascript 如何在react中设置新数据的状态?
我刚开始研究reactjs并尝试从API检索数据:Javascript 如何在react中设置新数据的状态?,javascript,reactjs,Javascript,Reactjs,我刚开始研究reactjs并尝试从API检索数据: constructor(){ super(); this.state = {data: false} this.nextProps ={}; axios.get('https://jsonplaceholder.typicode.com/posts') .then(response => { nextProps= response; }); }
constructor(){
super();
this.state = {data: false}
this.nextProps ={};
axios.get('https://jsonplaceholder.typicode.com/posts')
.then(response => {
nextProps= response;
});
}
当承诺返回数据时,我希望将其分配给以下状态:
componentWillReceiveProps(nextProps){
this.setState({data: nextProps})
}
如何使用从API接收的数据更新状态?目前还没有设定状态
jsbin ref:惯例是在
componentDidMount
生命周期方法中进行AJAX调用。请查看React文档:
通过AJAX加载初始数据在componentDidMount中获取数据。当响应到达时,将数据存储在状态中,从而触发渲染 更新你的用户界面 因此,您的代码将成为:
类应用程序扩展了React.Component{
构造函数(){
超级();
this.state={data:false}
}
componentDidMount(){
axios.get()https://jsonplaceholder.typicode.com/posts')
。然后(响应=>{
this.setState({data:response.data[0].title})
});
}
render(){
返回(
{this.state.data}
)
}
}
ReactDOM.render()显示了使用1)jQuery和2)Axios库实现此功能的两种方法
完整代码:
class App extends React.Component {
constructor() {
super();
this.state = {
time1: '',
time2: ''
};
}
componentDidMount() {
axios.get(this.props.url)
.then(response => {
this.setState({time1: response.data.time});
})
.catch(function (error) {
console.log(error);
});
$.get(this.props.url)
.then(result => {
this.setState({time2: result.time});
})
.catch(error => {
console.log(error);
});
}
render() {
return (
<div>
<p>Time via axios: {this.state.time1}</p>
<p>Time via jquery: {this.state.time2}</p>
</div>
);
}
};
ReactDOM.render(
<App url={"http://date.jsontest.com/"} />, document.getElementById('content')
);
类应用程序扩展了React.Component{
构造函数(){
超级();
此.state={
时间1:“”,
时间2:“”
};
}
componentDidMount(){
get(this.props.url)
。然后(响应=>{
this.setState({time1:response.data.time});
})
.catch(函数(错误){
console.log(错误);
});
$.get(this.props.url)
。然后(结果=>{
this.setState({time2:result.time});
})
.catch(错误=>{
console.log(错误);
});
}
render(){
返回(
通过axios的时间:{this.state.time1}
通过jquery的时间:{this.state.time2}
);
}
};
ReactDOM.render(
,document.getElementById('content'))
);
您可以尝试下面的示例代码,如果需要进一步帮助,请告诉我
var YourComponentName = React.createClass({
componentDidMount: function() {
var that = this;
// Your API would be calling here and get response and set state here as below example
// Just an example here with AJAX something you can do that.
$.ajax({
url: 'YOURURL',
dataType: 'json',
type: 'POST',
data: data,
success: function(response) {
that.setState({data: response})
}
});
},
render: function() {
return ();
}
});
谢谢 直接从promise中调用setState
,无需通过Prop。我刚刚添加了您的代码,并对我的aswer进行了必要的更改。你想让我补充点什么还是回答你的问题。
var YourComponentName = React.createClass({
componentDidMount: function() {
var that = this;
// Your API would be calling here and get response and set state here as below example
// Just an example here with AJAX something you can do that.
$.ajax({
url: 'YOURURL',
dataType: 'json',
type: 'POST',
data: data,
success: function(response) {
that.setState({data: response})
}
});
},
render: function() {
return ();
}
});