Javascript 在嵌套的addEventListener函数中使用setState时,“this.setState不是函数”
我一生都无法在react组件中传递此类型错误。我已经阅读了每一个相关的线程,并实施了几乎所有建议的修复,但都没有效果Javascript 在嵌套的addEventListener函数中使用setState时,“this.setState不是函数”,javascript,reactjs,setstate,Javascript,Reactjs,Setstate,我一生都无法在react组件中传递此类型错误。我已经阅读了每一个相关的线程,并实施了几乎所有建议的修复,但都没有效果 import React, { Component } from "react"; class Wave extends Component { state = { position: 44 }; changePosition = () => { let parentDiv = document.getElemen
import React, { Component } from "react";
class Wave extends Component {
state = {
position: 44
};
changePosition = () => {
let parentDiv = document.getElementById('parentDiv');
//this.setState({position: 3})
parentDiv.addEventListener('click', function (e) {
let offset = this.getClientRects()[0];
alert(e.clientX - offset.left);
let xcord = e.clientX - offset.left;
this.setState({position: xcord})
}, false);
}
render() {
return (
<div id={"parentDiv"}>
<div id={"childDiv"} onClick={this.changePosition}>HI THERE!</div>
</div>
);
}
}
export default Wave;
但是,当我这样做时,以及当我尝试将addEventListener函数更改为箭头函数e=>{时,我留下了TypeError:this.getClientRects不是一个函数
任何关于如何避免这个错误的启示都是非常感谢的,因为这已经占用了我一天的最后2-3个小时。非常感谢
parentDiv.addEventListener('click', function (e) {
let offset = this.getClientRects()[0]; // this refers to parentDiv
}
将此更改为箭头函数以正确绑定此
使用parentDiv.getClientRects代替此..,使用arrow函数代替.bind以保持整洁。这很有效。非常感谢。
parentDiv.addEventListener('click', function (e) {
let offset = this.getClientRects()[0]; // this refers to parentDiv
}
parentDiv.addEventListener('click', (e) => {
let offset = parentDiv.getClientRects()[0]; // this refers to Wave component, so we use the actual div reference
alert(e.clientX - offset.left);
let xcord = e.clientX - offset.left;
this.setState({position: xcord}); // works fine
}, false);