如何将基于类的单选按钮组更改为基于功能的单选按钮

Question

这是基于类的无线电组。我想把它转换成基于功能的无线电组。我该怎么做。代码如下：

import React, { Component } from "react";
class Demo2 extends Component {
constructor() {
super();
this.state = {
name: "React"
};
this.onValueChange = this.onValueChange.bind(this);
this.formSubmit = this.formSubmit.bind(this);
}
onValueChange(event) {
this.setState({
selectedOption: event.target.value
});
}
formSubmit(event) {
event.preventDefault();
console.log(this.state.selectedOption)
}
render() {
return (
<form onSubmit={this.formSubmit}>
<div className="radio">
<label>
<input
type="radio"
value="Male"
checked={this.state.selectedOption === "Male"}
onChange={this.onValueChange}
/>
Male
</label>
</div>
<div className="radio">
<label>
<input
type="radio"
value="Female"
checked={this.state.selectedOption === "Female"}
onChange={this.onValueChange}
/>
Female
</label>
</div>

我想要它为基于功能的组件工作的代码。我是新手，请帮忙。

Answer 1

使用React.useState创建一个本地状态，并根据更新的状态更改模板。

*注：功能组件不需要-this运算符。而且你也可以直接返回模板(不需要渲染方法(

样本代码：

import React, { useState } from "react";
import "./styles.css";
export default function Demo2() {
const [selectedOption, setSelectedOption] = useState("Male");
const onValueChange = (event) => {
setSelectedOption(event.target.value);
};
const formSubmit = (event) => {
event.preventDefault();
console.log(selectedOption);
};
return (
<form onSubmit={formSubmit}>
<div className="radio">
<label>
<input
type="radio"
value="Male"
checked={selectedOption === "Male"}
onChange={onValueChange}
/>
Male
</label>
</div>
<div className="radio">
<label>
<input
type="radio"
value="Female"
checked={selectedOption === "Female"}
onChange={onValueChange}
/>
Female
</label>
</div>
<div>
<button type="submit">Submit</button>
</div>
</form>
);
}

工作代码-https://codesandbox.io/s/bold-platform-yr3l9?file=/src/App.js:0-1001

Answer 2

import React, { useState } from "react";
function Demo2() {
const [checked, setChecked] = useState("Male");
const onValueChange = (event) => {
setChecked(event.target.value);
};
const formSubmit = (event) => {
event.preventDefault();
console.log(checked);
};
return (
<form onSubmit={formSubmit}>
<div className="radio">
<label>
<input
type="radio"
value="Male"
checked={checked === "Male"}
onChange={onValueChange}
/>
Male
</label>
</div>
<div className="radio">
<label>
<input
type="radio"
value="Female"
checked={checked === "Female"}
onChange={onValueChange}
/>
Female
</label>
</div>
<div>
<button type="submit">Submit</button>
</div>
</form>
);
}