d3图表无法使用React

Question

按照示例页面尝试设置react + d3，我看到一个空白页面呈现。该指南位于https://dzone.com/articles/how-you-can-translate-any-random-d3-example-to-rea

完整的组件代码（虽然主要是复制+粘贴）：

import React, {Component} from 'react';
import * as topojson from 'topojson';
import * as d3 from 'd3';

class CongressionalDistricts extends Component {
    state = {
    usData: null,
    usCongress: null
}

componentWillMount() {
    // load data
    d3.queue()
        .defer(d3.json, "https://raw.githubusercontent.com/Swizec/113th-congressional-districts/master/public/us.json")
        .defer(d3.json, "https://raw.githubusercontent.com/Swizec/113th-congressional-districts/master/public/us-congress-113.json")
        .await((error, usData, usCongress) => {
            this.setState({
                usData,
                usCongress
            })
        })
}

componentDidUpdate() {
    // render example D3

    const svg = d3.select(this.refs.anchor)
    // const {width, height} = this.props;
    const width = 960;
    const height = 600;


    const projection = d3.geoAlbers()
        .scale(1280)
        .translate([width / 2, height / 2]);
    // console.log(projection);

    const path = d3.geoPath(projection);
    console.log('path');
    // console.log(path);

    const us = this.state.usData
    const congress = this.state.usCongress;
    console.log(topojson.feature(us, us.objects.land));
    console.log(us);
    console.log(congress);

    svg.append("defs").append("path")
        .attr("id", "land")
        .datum(topojson.feature(us, us.objects.land))
        .attr("d", path);

    svg.append("clipPath")
        .attr("id", "clip-land")
        .append("use")
        .attr("xlink:href", "#land");

    svg.append("g")
        .attr("class", "districts")
        .attr("clip-path", "url(#clip-land)")
        .selectAll("path")
        .data(topojson.feature(congress, congress.objects.districts).features)
        .enter().append("path")
        .attr("d", path)
        .append("title")
        .text(function (d) {
            return d.id;
        });

    svg.append("path")
        .attr("class", "district-boundaries")
        .datum(topojson.mesh(congress, congress.objects.districts, function (a, b) {
            return a !== b && (a.id / 1000 | 0) === (b.id / 1000 | 0);
        }))
        .attr("d", path);

    svg.append("path")
        .attr("class", "state-boundaries")
        .datum(topojson.mesh(us, us.objects.states, function (a, b) {
            return a !== b;
        }))
        .attr("d", path);
}

render() {
    const {usData, usCongress} = this.state;

    if (!usData || !usCongress) {
        return null;
    }

    return <g ref="anchor"/>;
}
}

检查控制台时我看到警告：

  

此浏览器中无法识别该标记。如果你打算渲染一个   React组件，以大写字母开头。

以及在0x0元素中可用。我尝试过硬编码以及从传递道具的父组件内渲染，但仍然看到现在的图表。我有什么想法吗？