React，使用gelElementById访问DOM，然后尝试用React组件替换节点

Question

如果我想用ReactJS节点替换DOM节点，怎么办？

const myComp = <span>hey</span>
const elem = document.getElementById('video1')
elem.parentNode.replaceChild(myComp, elem)

该怎么做？这不起作用

var temp = document.createElement('div')
ReactDOM.render(myComp, temp)
console.log(temp) // a node with the nested div element
console.log(temp.firstChild) // null (??)
console.log(temp.firstElementChild) // null (??)
elem.parentNode.replaceChild(temp.firstElementChild, elem) // error

Answer 1

const elem = document.getElementById('video1') 

...    

ReactDOM.render(myComp, elem)