ReactJS - Is there a way to trigger a method by pressing the 'Enter' key inside ?

问题

Using only onChange and value and while focused inside a <input/>, preferably without jQuery, is there a way to trigger a method by pressing the 'Enter' key? Because, would only want the user to press 'Enter' key in order to update the name string state.

Here is the code:

  constructor(props) {
    super(props);

    this.state = {
      name: '',
    }
  }

  textChange(event) {
    this.setState({
      name: event.target.value,
    })
  }

  //Would like to trigger this once 'Enter' key is pressed while focused inside `<input/>`
  enterPressed() {
    var name = this.state.name;
  }

  render() {
    return (
        <input
          placeholder='Enter name'
          onChange={this.textChange.bind(this)}
          value={this.state.name}
        />
    )
  }

回答1:

What you can do is use React's key events like so:

<input
    placeholder='Enter name'
    onChange={this.textChange.bind(this)}
    value={this.state.name} 
    onKeyPress={this.enterPressed.bind(this)}
/>

Now, to detect enter key, change the enterPressed function to:

enterPressed(event) {
    var code = event.keyCode || event.which;
    if(code === 13) { //13 is the enter keycode
        //Do stuff in here
    } 
}

So what this does is add an event listener to the input element. See React's Keyboard Events. The function enterPressed is then triggered on event, and now enterPressed detects the key code, and if it's 13, do some things.

Here's a fiddle demonstrating the event.

Note: The onKeyPress and onKeyDown events trigger instantaneously on user press. You can use onKeyUp to combat this.

回答2:

You can add a onKeyPress to your input and make it equal the function you want to execute . You would just need to make sure the key pressed was the enter key using the event that is passed to the function as an argument

Unfortunately can't just use the onchange method alone to get this result

回答3:

Use onKeyPress and the resulting event object's key property, which is normalised cross-browser for you by React:

<meta charset="UTF-8">
<script src="https://unpkg.com/react@15.3.1/dist/react.js"></script>
<script src="https://unpkg.com/react-dom@15.3.1/dist/react-dom.js"></script>
<script src="https://unpkg.com/babel-core@5.8.38/browser-polyfill.min.js"></script>
<script src="https://unpkg.com/babel-core@5.8.38/browser.min.js"></script>
<div id="app"></div>
<script type="text/babel">

var App = React.createClass({
  getInitialState() {
    return {
      name: ''
    }
  },
  handleChange(e) {
    this.setState({name: e.target.value})
  },
  handleKeyPress(e) {
    if (e.key === 'Enter') {
      alert('Enter pressed')
    }
  },
  render() {
    return <input
      placeholder='Enter name'
      onChange={this.handleChange}
      onKeyPress={this.handleKeyPress}
      value={this.state.name}
    />
  }
})

ReactDOM.render(<App/>, document.querySelector('#app'))

</script>

来源：https://stackoverflow.com/questions/39442419/reactjs-is-there-a-way-to-trigger-a-method-by-pressing-the-enter-key-inside

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