React.js - 如何設置選中/選中的單選按鈕並跟蹤 onChange？

Question

我在一個組件中有一個每周幾天的廣播組。 如果用戶已經有與他們的帳戶相關聯的一天，我希望它成為選中/選中的單選按鈕。 因此，如果他們之前保存了“星期一”，我將從父級獲取它並將其存儲在狀態中，並希望在頁面呈現時選擇它。

我試圖將其設置為類似於在 React Forms 中進行選擇的方式，但它似乎不適用於 Fieldset。 有什么想法嗎？

constructor(props) {
  super(props);
  this.state = {
    reportWeekday: "monday"
  }
}

  handleWeekdayChange(event){
    this.setState({reportWeekday: event.target.value});
    console.log(event.target.value);
  }

  <fieldset className="schedule-weekday" value={this.state.reportWeekday} onChange={this.handleWeekdayChange}>
    <label for="sunday"><input type="radio" name="schedule-weekly-option" value="sunday" id="sunday" />Sunday</label>
    <label for="monday"><input type="radio" name="schedule-weekly-option" value="monday" id="monday" />Monday</label>
    <label for="tuesday"><input type="radio" name="schedule-weekly-option" value="tuesday" id="tuesday" />Tuesday</label>
    <label for="wednesday"><input type="radio" name="schedule-weekly-option" value="wednesday" id="wednesday" />Wednesday</label>
    <label for="thursday"><input type="radio" name="schedule-weekly-option" value="thursday" id="thursday" />Thursday</label>
    <label for="friday"><input type="radio" name="schedule-weekly-option" value="friday" id="friday" />Friday</label>
    <label for="saturday"><input type="radio" name="schedule-weekly-option" value="saturday" id="saturday" />Saturday</label>
  </fieldset>

Answer 1

這是 Jonny 的解決方案，沒有啟用類屬性。

class ControlledRadios extends React.Component{
  constructor(){
    super()
    this.state = {
      reportWeekday: 'monday'
    }
  }

  handleWeekdayChange(event) {
    this.setState({reportWeekday: event.target.value})    
  }

  render() {
    let {reportWeekday} = this.state
    return (<fieldset onChange={this.handleWeekdayChange.bind(this)}>
      <label><input type="radio" name="schedule-weekly-option" value="sunday" checked={reportWeekday === 'sunday'}/>Sunday</label>
      <label><input type="radio" name="schedule-weekly-option" value="monday" checked={reportWeekday === 'monday'}/>Monday</label>
      <label><input type="radio" name="schedule-weekly-option" value="tuesday" checked={reportWeekday === 'tuesday'}/>Tuesday</label>
      <label><input type="radio" name="schedule-weekly-option" value="wednesday" checked={reportWeekday === 'wednesday'}/>Wednesday</label>
      <label><input type="radio" name="schedule-weekly-option" value="thursday" checked={reportWeekday === 'thursday'}/>Thursday</label>
      <label><input type="radio" name="schedule-weekly-option" value="friday" checked={reportWeekday === 'friday'}/>Friday</label>
      <label><input type="radio" name="schedule-weekly-option" value="saturday" checked={reportWeekday === 'saturday'}/>Saturday</label>
    </fieldset>)
    }

}

Answer 2

對於那些使用 UseState 鈎子的人，您可以簡單地執行以下操作：

    import React, { useState } from 'react';
    
    
    export default function ControlledRadios() {
    const [weekday,setWeekday] = useState("monday")
    
    function handleWeekdayChange(event) {
    setWeekday(event.target.value)
    }
    
    return {
    <fieldset className="schedule-weekday" value={weekday} onChange={(event) => handleWeekdayChange(event)}>
        <label for="sunday"><input type="radio" name="schedule-weekly-option" value="sunday" id="sunday" />Sunday</label>
        <label for="monday"><input type="radio" name="schedule-weekly-option" value="monday" id="monday" />Monday</label>
        <label for="tuesday"><input type="radio" name="schedule-weekly-option" value="tuesday" id="tuesday" />Tuesday</label>
        <label for="wednesday"><input type="radio" name="schedule-weekly-option" value="wednesday" id="wednesday" />Wednesday</label>
        <label for="thursday"><input type="radio" name="schedule-weekly-option" value="thursday" id="thursday" />Thursday</label>
        <label for="friday"><input type="radio" name="schedule-weekly-option" value="friday" id="friday" />Friday</label>
        <label for="saturday"><input type="radio" name="schedule-weekly-option" value="saturday" id="saturday" />Saturday</label>
      </fieldset>
    }

Answer 3

似乎在多個同名的不受控制的單選按鈕上設置defaultChecked並沒有像您期望的那樣工作，並且由於某種原因onChange每個不受控制的單選按鈕僅觸發一次（使用 react@15.6.1），因此您可能必須切換到通過設置checked 控制輸入。

class ControlledRadios extends React.Component {
  state = {
    reportWeekday: 'monday'
  }

  handleWeekdayChange = (event) => {
    this.setState({reportWeekday: event.target.value})
  }

  render() {
    let {reportWeekday} = this.state
    return <fieldset onChange={this.handleWeekdayChange}>
      <label><input type="radio" name="schedule-weekly-option" value="sunday" checked={reportWeekday === 'sunday'}/>Sunday</label>
      <label><input type="radio" name="schedule-weekly-option" value="monday" checked={reportWeekday === 'monday'}/>Monday</label>
      <label><input type="radio" name="schedule-weekly-option" value="tuesday" checked={reportWeekday === 'tuesday'}/>Tuesday</label>
      <label><input type="radio" name="schedule-weekly-option" value="wednesday" checked={reportWeekday === 'wednesday'}/>Wednesday</label>
      <label><input type="radio" name="schedule-weekly-option" value="thursday" checked={reportWeekday === 'thursday'}/>Thursday</label>
      <label><input type="radio" name="schedule-weekly-option" value="friday" checked={reportWeekday === 'friday'}/>Friday</label>
      <label><input type="radio" name="schedule-weekly-option" value="saturday" checked={reportWeekday === 'saturday'}/>Saturday</label>
    </fieldset>
  }
}

• 現場版