React native 每x秒更新一次状态
我正在尝试每3秒更新一个状态React native 每x秒更新一次状态,react-native,React Native,我正在尝试每3秒更新一个状态 export default class Calendar extends Component { constructor(props) { super(props); this.state = { timeLineTop: 75, }; } render() { this.state.timeLineTop = setInterval(function () { let d = new Date(
export default class Calendar extends Component {
constructor(props) {
super(props);
this.state = {
timeLineTop: 75,
};
}
render() {
this.state.timeLineTop = setInterval(function () {
let d = new Date();
let result = d.getHours() + d.getMinutes() / MINUTES_IN_HOUR;
return result;
}, 3000);
<View style={[
{ top: this.state.timeLineTop },
]}></View>
}
}
导出默认类日历扩展组件{
建造师(道具){
超级(道具);
此.state={
timeLineTop:75,
};
}
render(){
this.state.timeLineTop=setInterval(函数(){
设d=新日期();
让结果=d.getHours()+d.getMinutes()/MINUTES(以小时为单位);
返回结果;
}, 3000);
}
}
为什么不每3秒更新一次我的视图位置?**更新以实现TimerMixin 您需要调用this.setState来更新状态变量,并按照 @eyal83,将TimerMixin用于setTimeout和setInterval:
var TimerMixin = require('react-timer-mixin');
componentDidMount: function() {
this.setInterval( () => {
let d = new Date();
let result = d.getHours() + d.getMinutes() / MINUTES_IN_HOUR;
this.setState({
timeLineTop: result
})
}, 500);
}
我还设置了一个基本应用程序,用setInterval重置状态变量,代码如下
“严格使用”;
var React=require('React-native');
变量{
评估学,
样式表,
文本,
看法
}=反应;
var TimerMixin=require('react-timer-mixin');
var SampleApp=React.createClass({
mixin:[TimerMixin],
getInitialState:函数(){
返回{
时间表:75
}
},
componentDidMount:function(){
此.setInterval(()=>{
这是我的国家({
timeLineTop:this.state.timeLineTop+1
})
}, 500);
},
render:function(){
返回(
TOP-{this.state.timeLineTop}
);
}
});
var styles=StyleSheet.create({
容器:{
弹性:1,
玛金托普:60,
},
});
AppRegistry.registerComponent('SampleApp',()=>SampleApp);
全局使用setTimeout和setInterval是一个非常糟糕的主意
我们强烈反对使用全局setTimeout(…),建议您使用react timer mixin提供的.setTimeout(…)。这将消除跟踪bug的大量繁重工作,例如卸载组件后超时触发导致的崩溃
更多信息请点击此处:
包括计时器混音,如下所示:
var TimerMixin = require('react-timer-mixin');
var Component = React.createClass({
mixins: [TimerMixin],
componentDidMount: function() {
this.setInterval(
() => { console.log('I do not leak!'); },
500
);
}
});
在ES6中,应该使用react mixin,(),例如:
var reactMixin=require('react-mixin');
var someMixin=require('some-mixin');
类Foo扩展了React.Component{
render:function(){return}
}
reactMixin(Foo.prototype,someMixin);
reactMixin(Foo.prototype,someOtherMixin)代码>ES6解决方案对我有效,我在这里找到了它
此代码在React Native 0.47.1中工作
import TimerMixin from 'react-timer-mixin';
mixins: [TimerMixin];
export class MyClass extends Component {
componentDidMount() {
this.interval = setInterval(() => {
console.log("Hi");
}, 6000); //6 seconds
}
componentWillUnmount() {
clearInterval(this.interval);
}
}
这是我使用组件的代码
import TimerMixin from 'react-timer-mixin';
export default class MyComponent extends Component {
componentDidMount(){
TimerMixin.setTimeout.call(this, () =>{
this.getData()
},2000);
}
getData(){
//call API HERE
}
}
对于setTimeout和setInterval,确实应该使用TimerMixin。有关更多信息,请参见我的答案。如何对ES6课程执行相同的操作?Thanksimport TimerMixin来自'react timer mixin'类SomeComp扩展了react.class{mixins:[TimerMixin]componendimount(){this.setInterval(()=>{console.log('I not leak!');},500);}
import TimerMixin from 'react-timer-mixin';
mixins: [TimerMixin];
export class MyClass extends Component {
componentDidMount() {
this.interval = setInterval(() => {
console.log("Hi");
}, 6000); //6 seconds
}
componentWillUnmount() {
clearInterval(this.interval);
}
}
import TimerMixin from 'react-timer-mixin';
export default class MyComponent extends Component {
componentDidMount(){
TimerMixin.setTimeout.call(this, () =>{
this.getData()
},2000);
}
getData(){
//call API HERE
}
}