javascript - 函数组件不支持contextType

Question

Function components do not support contextType.

我在尝试向用 React Router withRouter(...) 函数包装的 React 组件添加上下文时遇到问题。

import React, { Component } from 'react'
import UserContext from './UserContext'
class Toolbar extends Component {
  render(){
    return (
      <div>username: this.context.username</div>
    )
  }
}
Toolbar.contextType = UserContext
export default withRouter(Toolbar)

Answer 1

这个问题的解决方案就是像这样简单地切换最后两行:

export default withRouter(Toolbar)
Toolbar.contextType = UserContext