ng g c component/steps

import { Component, OnInit} from '@angular/core';

@Component({
 selector: 'app-steps',
 templateUrl: './steps.component.html',
 styleUrls: ['./steps.component.css']
})
export class StepsComponent implements OnInit {
 constructor() { }
 ngOnInit() { }
}

<div class="steps">
 <ul class="lineUl">
  <li *ngFor="let item of stepsData; let i=index" [ngClass]="{'liWidth': i+1 == stepsData.length}">
   <div class="stepsIcon">
    <div class="radioSelect radioSelectDisabled" [ngClass]="{'radioSelectDisabled': i+1>active}"></div>
    <div *ngIf="i+1 != stepsData.length" class="line" [ngClass]="{'lineDefaule': i+2>active}">
     <span *ngIf="!!item.tips">{{item.tips}}</span>
    </div>
   </div>
  </li>
 </ul>

 <ul class="text">
  <li *ngFor="let item of stepsData; let i=index">
    <div class="title" *ngIf="!!item.title">{{item.title}}</div>
    <div class="description" *ngIf="!!item.description">{{item.description}}</div>
  </li>
 </ul>
</div>

import { Component, OnInit, Input } from '@angular/core';
//引入Input
@Component({
 selector: 'app-steps',
 templateUrl: './steps.component.html',
 styleUrls: ['./steps.component.css']
})
export class StepsComponent implements OnInit {

 @Input() stepsData:any;
 @Input() active:string;
 constructor() { }

 ngOnInit() {
  console.log(!!!this.active)
  if(!!!this.active){
   this.active="1";
  }
 }

}

.steps ul{
  display: flex;
}

li{
  width: 100%;
  text-align: center;
}

.lineUl{
  padding: 0px 10%;
  margin-bottom: 5px;
}

.liWidth{
  width: 20px;
}

.stepsIcon{
  display: flex;
}

.radioSelect {
 box-sizing: border-box;
 display: inline-block;
 border-radius: 100%;
 border: 1px solid #26a2ff;
 position: relative;
 width: 20px;
 height: 20px;
 vertical-align: middle;
 background-color: #26a2ff;
}

.radioSelect::after {
 border: 2px solid transparent;
 border-left: 0;
 border-top: 0;
 content: ' ';
 top: 3px;
 left: 6px;
 position: absolute;
 width: 4px;
 height: 8px;
 border-color: #fff;
 -webkit-transform: rotate(45deg) scale(1);
 transform: rotate(45deg) scale(1);
 -webkit-transition: -webkit-transform 0.2s;
 transition: -webkit-transform 0.2s;
 transition: transform 0.2s;
 transition: transform 0.2s, -webkit-transform 0.2s;
}

.radioSelectDisabled {
  background-color: #d9d9d9;
  border-color: #ccc;
}

.line{
  display: block;
  flex: 1;
  height: 16px;
  border-bottom: 1px solid#26a2ff;
  margin-top: -5px;
  font-size: 12px;
  color: #26a2ff;
}

.lineDefaule{
  border-bottom: 1px solid#d9d9d9;
}

.title{
  font-size: 14px;
}

.description{
  font-size: 12px;
}

<app-steps [stepsData]="stepsData" [active]='3'></app-steps>

 public stepsData:any = [
  {
   title:'步骤1',
   description:'描述文件'
  },
  {
   title:'步骤2',
   description:'描述文件'
  },
  {
   title:'步骤3',
   description:'描述文件',
   tips:'待开奖'
  },
  {
   title:'步骤4',
   description:'描述文件'
  }
 ];

//stepsData:步骤条参数
//active：设置当前激活步骤，默认为1