Echarts 折线图根据容器宽度自适应展示
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需求描述
如上图所见，在开发过程中经常会遇到容器自适应展示的功能，那么如果在需要自适应宽高的容器内，echarts折线图要怎么处理呢？
改造前代码实现流程
import React, { useRef, useEffect } from 'react';
import ReactDom from 'react-dom';
import * as echarts from 'echarts';
const Test = () => {
const divRef = useRef < HTMLDivElement > (null);
const chart = useRef < echarts.ECharts > (null);
const fontColor = "#30eee9";
useEffect(() => {
if (!divRef.current) return;
let myChart = chart.current;
if (!myChart) {
chart.current = myChart;
myChart = echarts.init(divRef.current);
const option = {
backgroundColor: "#11183c",
grid: {
left: "5%",
right: "10%",
top: "20%",
bottom: "15%",
containLabel: true,
},
tooltip: {
show: true,
trigger: "item",
},
legend: {
show: true,
x: "center",
y: "35",
icon: "stack",
itemWidth: 10,
itemHeight: 10,
textStyle: {
color: "#1bb4f6",
},
data: ["已采纳", "已发布"],
},
xAxis: [
{
type: "category",
boundaryGap: false,
axisLabel: {
color: fontColor,
},
axisLine: {
show: true,
lineStyle: {
color: "#397cbc",
},
},
axisTick: {
show: false,
},
splitLine: {
show: false,
lineStyle: {
color: "#195384",
},
},
data: [
"1月",
"2月",
"3月",
"4月",
"5月",
"6月",
"7月",
"8月",
"9月",
"10月",
"11月",
"12月",
],
},
],
yAxis: [
{
type: "value",
name: "",
min: 0,
max: 1000,
axisLabel: {
formatter: "{value}",
textStyle: {
color: "#2ad1d2",
},
},
axisLine: {
lineStyle: {
color: "#27b4c2",
},
},
axisTick: {
show: false,
},
splitLine: {
show: true,
lineStyle: {
color: "#11366e",
},
},
},
],
series: [
{
name: "已采纳",
type: "line",
stack: "总量",
symbol: "circle",
symbolSize: 8,
itemStyle: {
normal: {
color: "#0092f6",
lineStyle: {
color: "#0092f6",
width: 1,
}
},
},
markPoint: {
itemStyle: {
normal: {
color: "red",
},
},
},
data: [120, 132, 101, 134, 90, 230, 210, 182, 191, 234, 290, 330],
},
{
name: "已发布",
type: "line",
stack: "总量",
symbol: "circle",
symbolSize: 8,
itemStyle: {
normal: {
color: "#00d4c7",
lineStyle: {
color: "#00d4c7",
width: 1,
},
},
},
data: [220, 182, 191, 234, 290, 330, 310, 201, 154, 190, 330, 410],
},
],
};
option && myChart.setOption(option);
}
}, []);
return <div style={{ width: '100%', height: 280 }} ref={divRef}/>
};
代码思路
以上的功能实现是基于react 和 react hook，在页面展示前先获取dom元素，如果dom成功获取到以后，为这个dom插入option相关的配置，那么现在并没有根据容器的宽度自适应的显示折线图，现在是把获取dom和渲染的方法放在了useEfft中，那么要如何监听自身的容器宽高，并动态的渲染变化呢？？
处理方案
使用ResizeObserver对象来监听指定Dom元素(div…)的变化(width、height等等)。一般，浏览器不支持该监听对象，所以需要引入第三方库支持-resize-observer-polyfill
第一步，安装 npm install resize-observer-polyfill；
第二步，页面中引入 import ResizeObserver from 'resize-observer-polyfill';
第三步， 利用 ResizeObserver 对渲染折线图的dom进行监听，如果监听到渲染折线图所在的dom元素宽高发生变化，利用echarts本身提供的resize事件重绘。
第四部， 页面销毁时，取消所有被ResizeObserver对象监听的节点
最终代码
import React, { useRef, useEffect } from 'react';
import ReactDom from 'react-dom';
import * as echarts from 'echarts';
// 关键代码
import ResizeObserver from 'resize-observer-polyfill';
const Test = () => {
const divRef = useRef < HTMLDivElement > (null);
const chart = useRef < echarts.ECharts > (null);
// 关键代码
const myObserver = useRef < ResizeObserver > (null);
const fontColor = "#30eee9";
useEffect(() => {
if (!divRef.current) return;
let myChart = chart.current;
if (!myChart) {
chart.current = myChart;
myChart = echarts.init(divRef.current);
const option = {
backgroundColor: "#11183c",
grid: {
left: "5%",
right: "10%",
top: "20%",
bottom: "15%",
containLabel: true,
},
tooltip: {
show: true,
trigger: "item",
},
legend: {
show: true,
x: "center",
y: "35",
icon: "stack",
itemWidth: 10,
itemHeight: 10,
textStyle: {
color: "#1bb4f6",
},
data: ["已采纳", "已发布"],
},
xAxis: [
{
type: "category",
boundaryGap: false,
axisLabel: {
color: fontColor,
},
axisLine: {
show: true,
lineStyle: {
color: "#397cbc",
},
},
axisTick: {
show: false,
},
splitLine: {
show: false,
lineStyle: {
color: "#195384",
},
},
data: [
"1月",
"2月",
"3月",
"4月",
"5月",
"6月",
"7月",
"8月",
"9月",
"10月",
"11月",
"12月",
],
},
],
yAxis: [
{
type: "value",
name: "",
min: 0,
max: 1000,
axisLabel: {
formatter: "{value}",
textStyle: {
color: "#2ad1d2",
},
},
axisLine: {
lineStyle: {
color: "#27b4c2",
},
},
axisTick: {
show: false,
},
splitLine: {
show: true,
lineStyle: {
color: "#11366e",
},
},
},
],
series: [
{
name: "已采纳",
type: "line",
stack: "总量",
symbol: "circle",
symbolSize: 8,
itemStyle: {
normal: {
color: "#0092f6",
lineStyle: {
color: "#0092f6",
width: 1,
}
},
},
markPoint: {
itemStyle: {
normal: {
color: "red",
},
},
},
data: [120, 132, 101, 134, 90, 230, 210, 182, 191, 234, 290, 330],
},
{
name: "已发布",
type: "line",
stack: "总量",
symbol: "circle",
symbolSize: 8,
itemStyle: {
normal: {
color: "#00d4c7",
lineStyle: {
color: "#00d4c7",
width: 1,
},
},
},
data: [220, 182, 191, 234, 290, 330, 310, 201, 154, 190, 330, 410],
},
],
};
//关键代码， 利用observe监听折线图所在容器的宽度变化（divRef.current），在ResizeObserver回掉函数中entries返回的内容可以获取的到；最后将获取到宽度赋值给resize方法进行重绘
myObserver.current = new ResizeObserver((entries) => {
myChart?.resize(entries[0]?.contentRect.width);
});
myObserver.current.observe(divRef.current);
myChart.setOption(option);
}
//关键代码
return () => {
if (chart?.current) chart.current.dispose();
//取消所有被ResizeObserver对象监听的节点
myObserver.current?.disconnect();
};
}, []);
return (
<div className='line' style={{ width: '100%', height: 280 }} ref={divRef} />
)
};