javascript - 输入键后清除文本区域

Question

我想在按下回车键后清除文本区域的内容。然而，当按下回车键时，文本区域被清除但回车键仍然存在(新行)。我怎样才能解决这个问题？

constructor(){
    this.state = { text : '' }
}

keypress(e){ 
   if(e.key == 'Enter'){
      this.setState({
        send_message: ''
      })
   }
}

<textarea value={this.state.text} placeholder="Text" rows="1" className="form-textarea typing-area" onKeyPress={this.keypress.bind(this)}></textarea>

Answer 1

当键为“Enter”时，您可以使用event.preventDefault:

class App extends React.Component {
  constructor(props) {
    super(props);
    this.state = { text : '' }
    this.handleChange = this.handleChange.bind(this);
    this.keypress = this.keypress.bind(this);
  }
  
  handleChange(event) {
    this.setState({text: event.target.value});
  }
  
  keypress(e){ 
    if(e.key === 'Enter'){
      e.preventDefault();
      this.setState({
        send_message: this.state.text,
        text: '',
      });
    }
  }
  render() {
    return (
      <div>
        <textarea 
          value={this.state.text} 
          placeholder="Text" 
          rows="1" 
          className="form-textarea typing-area" 
          onChange={this.handleChange}
          onKeyPress={this.keypress} 
        />
        <pre>{JSON.stringify(this.state, null, 2)}</pre>
      </div>
    );
  }
}

ReactDOM.render(<App />, document.getElementById('app'));

<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>
<div id="app"></div>