const [state,setState]=useState(0)
return(
<>
{state}
<div onClick={setState(1)}></div>
</>
)
//Error
//Too many re-renders. React limits the number of renders to prevent an infinite loop.
当我们使用{onClick={()=>setState(1)}}时,代码可以工作,但是我想知道为什么在第一种情况下它不能
我有一个动态输入,我可以添加和删除带有输入的行,还有资料输入-用于时间选择器的ui,当我单击它时,会出现带有她的时钟图标的输入。但是这个输入的值不能随着时钟的变化而改变。
我的代码是:
import { TimePicker } from "material-ui-time-picker";
import {
Input as Time,
Dialog as Clock,
DialogActions,
Button as ButtonOk
} from "@material-ui/core";
constructor(props) {
如何从两个不同的函数调用修改状态?下面的代码给出了错误“‘Maximum update depth exceedeed.”
class App extends Component {
// fires before component is mounted
constructor(props) {
// makes this refer to this component
super(props);
// set local state
this.state = {
date: new Date(),
myQues
看看react教程,它解释了当我们设置事件侦听器时,我们通常必须绑定函数上下文,就像这里所做的那样 class Toggle extends React.Component {
constructor(props) {
super(props);
this.state = {isToggleOn: true};
// This binding is necessary to make `this` work in the callback
this.handleClick = this.handleClick.bind(this);
}
han
请帮助理解React setState实际工作的本质。下面是一个例子:
class App extends React.Component { // first example
state = {
clicks: 0
};
handleButtonClick = this.handleButtonClick.bind(this);
handleButtonClick() {
this.setState({ // like this? Or should we use callback instead of object?
clicks: t
我正在尝试创建一个表,并呈现一些具有“隐藏”行能力的行。
以下是我要做的事:
var Child = React.createClass({
render: function() {
return(
<tr>
<td colSpan="8"> I am a child that can be hidden!</td>
</tr>
)
}
})
var CreateRows = React.create
我正在尝试将这个javascript文件转换为类型记录。但是,我在onClick函数上得到了一个错误,如下所示:
import React from 'react';
import { Popover } from 'antd';
import A from './A';
import B from './B';
class Demo extends React.Component {
state = {
visible: false,
btnName : "Button A",
se
我有一个动态输入,我可以添加和删除一行输入,有输入的材料-ui的时间选择器,它有一个输入与她的图标的时钟,当我点击它时,时钟将出现。但此输入的值不能随时钟变化。 我的代码是: import { TimePicker } from "material-ui-time-picker";
import {
Input as Time,
Dialog as Clock,
DialogActions,
Button as ButtonOk
} from "@material-ui/core";
constructor(props) {
sup
我是个新手。我用React JS写了下面的代码,我的代码不能编译。 class Message extends Component
{
constructor()
{
super(); //Since we are extending another class, it is mandatory
//this.state is an object
this.state = {
message: "Initial Message"
}
}
changeMess