React继续专注于Blur

Question

我有一个组件在focus()和componentDidMount期间在引用组件上触发componentDidUpdate。另外，当我们点击外面时，我的功能不会触发onClose。当我点击onBlur外部时，我再次触发focus以继续关注元素。什么是最好的方法？为什么在某些情况下我看到更好地使用setTimeout onblur？

export class Test extends Component {
    componentDidMount = () => this.focusContainer()
    componentDidUpdate = () => this.focusContainer()

    container = React.createRef()
    focusContainer = () => this.container.current.focus()

    render = () => {
       return (
         <div
                style={{outline: 'none'}}
                onKeyPress={this.captureInput}
                onBlur={this.focusContainer} // or                 onBlur={() => setTimeout(() => this.focusContainer(), 0) } - why ?

                ref={this.container}
                // tabIndex is needed for focus/blur to work on non input type elements.
                tabIndex={0}
            >
              <img src={scanTag} style={{maxWidth: '100%'}} alt='scan tag via scanner' />
          ..........
    </div>
       )
    }
}