react 进度条

js 部分

import React, { Component } from 'react'

import './index.less';
export default class index extends Component {
  constructor(props) {
    super(props);
    this.state={
      progressValue: 0, // 进度条背景宽度
      percentage: 0, // 进度条百分比
    }
  }

  handleBtn = () => {
    let { progressValue, percentage} = this.state;
    let timer = null;
    if (timer == null) {
      timer = setInterval(() => {
        progressValue += 10;
        // 这里的算法很重要，进度条容器的宽度为 400px 所以这里除以400再乘100就能得到 1-100的百分比了。
        percentage = Math.round(progressValue/400*100);
        if (progressValue >= 400) {
          percentage=100;
          progressValue=400;
          clearInterval(timer)
        }
        this.setState({ progressValue, percentage })
      }, 100);
    }
    
  }

  render() {
    return (
      <div className='progress-box'>
        <div className='progress-group'>
          <span>{this.state.percentage}%</span>
          <div className='progress-bg' style={{ width: this.state.progressValue}}></div>
        </div>
        <button onClick={this.handleBtn}>安装</button>
      </div>
    )
  }
}

 

css 部分

.progress-box {
  padding: 20px;
  width: 400px;
  .progress-group {
    width: 100%;
    height: 30px;
    position: relative;
    border: 1px solid #D72672;
    .progress-bg {
      width: 0px;
      height: 100%;
      display: flex;
      justify-content: center;
      align-items: center;
      background: #D72672;
    }
    span {
      position: absolute;
    }
  }
  button {
    margin-top: 20px;
  }
}