【Angular5】 返回前一页面 go back to previous page

import { Component, OnInit } from '@angular/core';
import { Router} from '@angular/router';
import { Location } from '@angular/common';
@Component({
  selector: 'app-notfound',
  templateUrl: './notfound.component.html',
  styleUrls: ['./notfound.component.scss']
})
export class NotfoundComponent implements OnInit {
  constructor(public _router: Router, private _location: Location) { }
  ngOnInit() {
  }
  goBack() {
    this._location.back();
  }
}