我无法自动聚焦此组件中呈现的输入标签。我在这里错过了什么？

class TaskBox extends Component {
  constructor() {
    super();
    this.focus = this.focus.bind(this);
  }

  focus() {
    this.textInput.focus();
  }

  componentWillUpdate(){
    this.focus();
  }

  render() {
    let props = this.props;
    return (
      <div style={{display: props.visible ? 'block' : 'none'}}>
        <input
        ref={(input) => { this.textInput = input; }}
        onBlur={props.blurFN} />
        <div>
          <div>Imp.</div>
          <div>Urg.</div>
          <div>Role</div>
        </div>
        <div>
          <button>Add goal</button>
        </div>
      </div>
    )
  }
}

任何帮助表示赞赏。