如何从 reactJS 中的无线电表单中获取价值

Question

I Have this form in one of my react components

      <div className="form-check">
        <input
          type="radio"
          className="form-check-input"
          value={3}
          name="priority"
        />
        <label className="form-check-label">High Priority</label>
      </div>
      <div className="form-check">
        <input
          type="radio"
          value={2}
          className="form-check-input"
          name="priority"
        />
        <label className="form-check-label">Medium Priority</label>
      </div>
      <div className="form-check">
        <input
          type="radio"
          value={1}
          className="form-check-input"
          name="priority"
        />
        <label className="form-check-label">Low Priority</label>
      </div>

I then have an onclick function on a button. I want to get the value of the radio form in my function. How do I do that? Is there a way to do it with the useRef hook? Note: I am using functional components so any solution with class components will not help.

Thank you!

Answer 1

Use state to maintain the value of the selected radio input.

We add one listener to the parent element so we can use event delegation which calls a function when it captures a change event from a child input element. When it's called it checks the clicked element is an input (radio) and then sets the state with its value.

The button simply logs the current state.

 const { useState } = React; function Example() { // Initialise state const [ radio, setRadio ] = useState(0); // When the button is clicked log the current state function handleClick(e) { console.log(radio); } // When an element is clicked function handleChange(e) { // Grab the nodeName and value from // the clicked element const { nodeName, value } = e.target; // Because we're using event delegation (attaching // an event listener to a parent element and capturing // events from child elements as they "bubble up" the DOM) // we need to check to see if the clicked element is an input if (nodeName === 'INPUT') { // Set the state with the input value setRadio(value); } } return ( <div onChange={handleChange}> <div className="form-check"> <input type="radio" className="form-check-input" value={3} name="priority" /> <label className="form-check-label">High Priority</label> </div> <div className="form-check"> <input type="radio" value={2} className="form-check-input" name="priority" /> <label className="form-check-label">Medium Priority</label> </div> <div className="form-check"> <input type="radio" value={1} className="form-check-input" name="priority" /> <label className="form-check-label">Low Priority</label> </div> <button onClick={handleClick}>Show radio state</button> </div> ); }; ReactDOM.render( <Example />, document.getElementById('react') );

 button { margin-top: 0.5em; }

 <script src="https://cdnjs.cloudflare.com/ajax/libs/react/17.0.2/umd/react.production.min.js"></script> <script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/17.0.2/umd/react-dom.production.min.js"></script> <div id="react"></div>

Answer 2

I have created demo here, you could add onChange method to each input and then save inside in a state.

Demo:https://codesandbox.io/s/tender-sinoussi-1t7fi?file=/src/App.js