Chart.js功能与使用方法小结

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本文实例讲述了Chart.js功能与使用方法。分享给大家供大家参考，具体如下：

官方文档

英文文档 https://www.chartjs.org/docs/2.8.0/
中文文档 https://chartjs-doc.abingoal.com

在react中的使用

开始使用

npm install chart.js --save

在相应的页面中引入 chartjs

import Chart from "chart.js"

先写一个小的demo

import React from "react";
import ReactDOM from "react-dom";

import Chart from "chart.js";

class App extends React.Component {
 constructor(props) {
  super(props);
  this.state = {};
 }
 componentDidMount() {
 this.renderCanvas()
 }

 // 作图
 renderCanvas = () => {
  const myChartRef = this.chartRef.getContext("2d");
  new Chart(myChartRef, {
   type: "line",
   data: {
    labels: [1,2,3,4,5],
    datasets: [
     {
      data: [10, 20, 50, 80, 100],
      backgroundColor: "rgba(71, 157, 255, 0.08)",
      borderColor: "rgba(0, 119, 255, 1)",
      pointBackgroundColor: "rgba(56, 96, 244, 1)",
      pointBorderColor: "rgba(255, 255, 255, 1)",
      pointRadius: 4
     }
    ]
   },
   
   options: {
    responsive: true,
    legend: {
     display: false
    },
    maintainAspectRatio: false
   }
  });
 };

 render() {
  return (
   <div style={{ height: 288 }}>
    <canvas id="myChart" ref={ref => (this.chartRef = ref)} />
   </div>
  );
 }
}

const rootElement = document.getElementById("root");
ReactDOM.render(<App />, rootElement);

https://codesandbox.io/embed/aged-meadow-2sc8m?fontsize=14

动态更新的数据

import React from "react";
import ReactDOM from "react-dom";

import Chart from "chart.js";
let currentChart;

class App extends React.Component {
 constructor(props) {
  super(props);
  this.state = {
   data: [30, 60, 90, 120, 100]
  };
 }
 componentDidMount() {
  this.renderCanvas();
  this.renderCurrent();
 }

 // 作图
 renderCanvas = () => {
  const myChartRef = this.chartRef.getContext("2d");
  new Chart(myChartRef, {
   type: "line",
   data: {
    labels: [1, 2, 3, 4, 5],
    datasets: [
     {
      data: [10, 20, 50, 80, 100],
      backgroundColor: "rgba(71, 157, 255, 0.08)",
      borderColor: "rgba(0, 119, 255, 1)",
      pointBackgroundColor: "rgba(56, 96, 244, 1)",
      pointBorderColor: "rgba(255, 255, 255, 1)",
      pointRadius: 4
     }
    ]
   },

   options: {
    responsive: true,
    legend: {
     display: false
    },
    maintainAspectRatio: false
   }
  });
 };

 renderCurrent = () => {
  const { data } = this.state;
  const currentCharttemp = this.currentChart.getContext("2d");
  if (typeof currentChart !== "undefined") {
   currentChart.destroy();
  }
  currentChart = new Chart(currentCharttemp, {
   type: "line",
   data: {
    labels: [1, 2, 3, 4, 5],
    datasets: [
     {
      data: data,
      backgroundColor: "rgba(71, 157, 255, 0.08)",
      borderColor: "rgba(0, 119, 255, 1)",
      pointBackgroundColor: "rgba(56, 96, 244, 1)",
      pointBorderColor: "rgba(255, 255, 255, 1)",
      pointRadius: 4
     }
    ]
   },

   options: {
    responsive: true,
    legend: {
     display: false
    },
    maintainAspectRatio: false
   }
  });
 };

 render() {
  return (
   <div>
    <canvas id="myChart" ref={ref => (this.chartRef = ref)} />
    <br />

    <button
     onClick={()=>
      this.setState({ data: [200, 500, 20, 50, 100] }, this.renderCurrent)
     }
    >
     更新数据
    </button>
    <canvas id="currentChart7" ref={ref => (this.currentChart = ref)} />
   </div>
  );
 }
}

感兴趣的朋友可以使用在线HTML/CSS/JavaScript代码运行工具：http://tools.jb51.net/code/HtmlJsRun测试上述代码运行效果。

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希望本文所述对大家JavaScript程序设计有所帮助。

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