可以在路由时重新调用饼图数据并渲染图表。

例如，假设我们有一个名为“piechart.component”的组件，它包含饼图代码，我们可以在该组件的“ngOnInit”生命周期钩子中初始化饼图：

import * as d3 from 'd3';

@Component({
  selector: 'app-piechart',
  templateUrl: './piechart.component.html',
  styleUrls: ['./piechart.component.scss']
})
export class PiechartComponent implements OnInit {
  data = [1, 2, 3, 4, 5];
  private svg;
  private margin = 50;
  private width = 300;
  private height = 300;
  private radius = Math.min(this.width, this.height) / 2 - this.margin;
  private colors;

  constructor() { }

  ngOnInit(): void {
    this.createSvg();
    this.createColors();
    this.drawChart();
  }

  private createSvg(): void {
    this.svg = d3.select("figure#chart")
    .append("svg")
    .attr("width", this.width)
    .attr("height", this.height)
    .append("g")
    .attr(
      "transform",
      "translate(" + this.width / 2 + "," + this.height / 2 + ")"
    );
  }

  private createColors(): void {
    this.colors = d3.scaleOrdinal()
    .domain(this.data)
    .range(["#c7d3ec", "#a5b8db", "#879cc4", "#677795", "#5a6782"]);
  }

  private drawChart(): void {
    const pie = d3.pie().value((d: any) => Number(d));
    const data_ready = pie(this.data);


    this.svg.selectAll('whatever')
    .data(data_ready)
    .enter()
    .append('path')
    .attr('d', d3.arc()
      .innerRadius(0)
      .outerRadius(this.radius)
    )
    .attr('fill', (d, i) => (this.colors(i)))
    .attr("stroke", "black")
    .style("stroke-width", "2px