props.children是否会成为无状态组件？

Question

我试图在反应中练习渲染道具，但是我遇到了错误

this.props.children不是函数

这是我的代码

import React from 'react';
import { render } from 'react-dom';


const Box = ({color}) => (
  <div>
    this is box, with color of {color}
  </div>
);

class ColoredBox extends React.Component {
  state = { color: 'red' }
  getState() {
    return {
      color: this.state.color
    }
  }
  render() {
    return this.props.children(this.getState())
  }
}

render(<ColoredBox><Box /></ColoredBox>, document.getElementById('root'));

https://codesandbox.io/s/8z0xmk9ojl

Answer 1

遵循渲染道具模式，您需要将子级作为函数，因此您确实可以编写

import React from 'react';
import { render } from 'react-dom';


const Box = ({color}) => (
  <div>
    this is box, with color of {color}
  </div>
);

class ColoredBox extends React.Component {
  state = { color: 'red' }
  getState() {
    return {
      color: this.state.color
    }
  }
  render() {
    return this.props.children(this.getState())
  }
}

render(<ColoredBox>{(color) => <Box color={color}/>}</ColoredBox>, document.getElementById('root'));

另外要明确的是，当您像这样渲染无状态功能组件时，它不会被视为与函数相同<Box/>

但是您可以使用上面的无状态功能组件，例如

<ColoredBox>{Box}</ColoredBox>

它会起作用

演示