javascript - 如何在 react 中设置多个复选框的处理程序？

Question

我在我的小项目中创建了多个复选框。我在给出复选标记时检索复选框的信息时遇到问题。如果我在玩具上打勾，那么值应该是玩具，或者如果我在玩具和灯上都打勾，我应该得到玩具和控制台上的灯。

这里是代码:

import React from "react";
import { render } from "react-dom";
import { Segment, Form, Checkbox, Button } from "semantic-ui-react";
import axios from "axios";
export default class ShowForm extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
      event: ""
    };
  }
  handleCheck = event => {
    console.log("Hello", event);
  };
  render() {
    return (
      <div>
        <Segment>
          <Form>
            <Checkbox label="Cake" onChange={this.handleCheck} />
            <br />
            <Checkbox label="Lights" onChange={this.handleCheck} />
            <br />
            <Checkbox label="Flowers" onChange={this.handleCheck} />
            <br />
            <Checkbox label="Toys" onChange={this.handleCheck} />
            <br />
            <Button onClick={this.handleSubmit}> Submit </Button>
          </Form>
        </Segment>
      </div>
    );
  }
}

以下是完整代码:“https://codesandbox.io/s/zealous-paper-p9zb5 ”

有人可以帮我解决这个问题吗？

Answer 1

您需要一个数组来存储所有选中的状态。

handleCheck = id => () => {                      // Get indentify from each element
  const { checkedList } = this.state;
  const result = checkedList.includes(id)        // Check if checked at this moment
    ? checkedList.filter(x => x !== id)          // If checked, remove
    : [...checkedList, id];                      // If not, add
  this.setState({ checkedList: result }, () => { // setState
    console.log(this.state.checkedList);         // setState is async, log in callback
  });
};

如果您愿意，您可以将 Checkbox 组件设为通用组件，这样您就无需在每个组件的三个位置绑定(bind) label。

<Checkbox
  label="Cake"
  onChange={this.handleCheck("Cake")}
  checked={checkedList.includes("Cake")}   // If included, checked
/>

<小时/>

另一个最低限度可重现的演示

尝试一下文本:

const list = [...Array(10).keys()].map(x => ({ id: x }));
const App = () => {
  const [selected, setSelected] = React.useState([]);
  const onChangeHandler = id => () => {
    selected.includes(id)
      ? setSelected(selected.filter(x => x !== id))
      : setSelected([...selected, id]);
  };
  const onRemove = () => {
    setSelected([]);
  };
  return (
    <div className="App">
      {list.map(item => (
        <input
          type="checkbox"
          key={item.id}
          checked={selected.includes(item.id)}
          onChange={onChangeHandler(item.id)}
        />
      ))}
      <br />
      <button onClick={onRemove}>Remove all</button>
      <div>{selected.join(",")}</div>
    </div>
  );
}
ReactDOM.render(<App />, document.getElementById("root"));

<div id="root"></div>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.12.0/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.12.0/umd/react-dom.production.min.js"></script>