index.js

import React, { Component } from 'react';
import ReactDOM from 'react-dom'
import { HashLoader } from "react-spinners";
import './loading.scss'


const container = document.body

class Loading extends Component {

    static defaultProps = {
        text: '加载中',
        fake: 0
    }

    state = {
        isLoading: true
    }

    componentDidMount() {
        if(!this.props.isLoading){
            this.setState({
                isLoading: false
            })
        }
    }


    componentDidUpdate(prevProps) {
        let {isLoading, fake} = this.props
        if (!isLoading) {
            if(fake){
                setTimeout(() => {
                    this.setState({
                        isLoading
                    })
                }, fake)
            }else {
                if(prevProps.isLoading != isLoading){
                    this.setState({
                        isLoading
                    })
                }
            }
        }
    }

    render() {
        const innerLoading =
            <div className="loading">
                <div className="loading-wrapper">
                    <HashLoader
                        css={{
                            display: 'block',
                            marginTop: '-100px'
                        }}
                        size={50}
                        color={'#09f'}
                    />
                    <p>{this.props.text}</p>
                </div>
            </div>

        return (
            this.state.isLoading ? ReactDOM.createPortal(innerLoading, container) : this.props.children
        );
    }
}

export default Loading;