静态渲染svg

import React from 'react';
import * as d3 from "d3";

class TestCharts extends React.Component {
  state = {

  };

  componentDidMount() {
    this.drawChart();
  }

  drawChart = ()=> {
    const data = [12, 5, 6, 6, 9, 10];
    const w = 300;
    const h = 200;

    const svg = d3.select(".D3")
      .append("svg")
      .attr("width", w)
      .attr("height", h)
      .style("margin-left", 100);

    svg.selectAll("rect")
      .data(data)
      .enter()
      .append("rect")
      .attr("x", (d, i) => i * 70)
      .attr("y", (d, i) => h - 10 * d)
      .attr("width", 65)
      .attr("height", (d, i) => d * 10)
      .attr("fill", "green")

  };

  render() {
    return (
      <div>
        <div className="D3" />
      </div>
    );
  }
}

export default TestCharts;

https://www.jianshu.com/p/b12291a5dcb7

动态渲染svg

const data = [12, 5, 6, 6, 9, 10];

const w = 700;
const h = 200;
let svg;


class TestCharts extends React.Component {
  state = {

  };

  componentDidMount() {
    this.drawChart()
    this.update()
  }
//  关键在于把enter和渲染分开
  drawChart = ()=> {
    svg = d3.select(".D3")
      .append("svg")
      .attr("width", w)
      .attr("height", h)

    svg.selectAll("rect")
      .data(data)
      .enter()
      .append("rect")

    this.renderChart(svg)
  }

  renderChart = () => {
    svg.selectAll("rect")
      .data(data)
      .attr("x", (d, i) => i * 70)
      .attr("y", (d, i) => h - 10 * d)
      .attr("width", 65)
      .attr("height", (d, i) => d * 10)
      .attr("fill", "green")
  }

  update = () => {
    setInterval(()=>{
      data.shift();
      data.push(Math.round(Math.random() * 20));
      this.renderChart()
    },1000)
  }

  render() {
    return (
      <div>
        <div className="D3" />
      </div>
    );
  }
}

export default TestCharts;

动态渲染Dom

import React from 'react';
import * as d3 from "d3";
import './index.less';

const data = [10, 15, 30, 50, 80, 65, 55, 30, 20, 10, 8];

class TestCharts extends React.Component {
  state = {

  };

  componentDidMount() {
    this.update()
    // this.mockData();
  }

  drawChart = ()=> {

    // enter
    d3.select(".D3").selectAll("div.h-bar")
      .data(data)
      .enter()
      .append("div")
      .attr("class", "h-bar")
      .append("span")

    // update
    d3.select(".D3").selectAll("div.h-bar")
      .data(data)
      .style("width", d=>`${d*3}px`)
      .select("span")
      .text(d=>d)

    // exit
    d3.select(".D3").selectAll("div.h-bar")
      .data(data)
      .exit()
      .remove()

  }

  update = () => {
    setInterval(()=>{
      data.shift();
      data.push(Math.round(Math.random() * 100));
      this.drawChart()
    },1000)
  }

  render() {
    return (
      <div>
        <div className="D3" />
      </div>
    );
  }
}

export default TestCharts;