I have been using echars for a long time. If a pie chart with the style shown above appears, it is difficult for me to use echarts. The official document does not have a pie chart in this mode. I tried using d3 and canvas to draw pie charts respectively. Because I am familiar with canvas and d3 also needs to introduce plug-ins, based on the principle of lightweight, I used canvas encapsulation.
There are two official pie chart modes: (1) Radius mode (2) Area mode
Implementation process(1) The encapsulated functions are as follows:
function drawCircle(canvasId, option) { const color_arr = option.color let data_arr = option.data const pi2 = Math.PI * 2; let canvas = document.getElementById(canvasId); let c = canvas.getContext(2d); let startAgl = 0; let agl; let sum = 0; const cW = canvas.width; const cH = canvas.height; for (let item of data_arr) { sum += item.value * 1.0 } data_arr = data_arr.map((v, i) => { return { name: v.name, value: (v.value) * 1.0 / sum } }) for (let i = 0; i < data_arr.length; i++) { //Draw a pie chart let min = (cW > cH ? cH : cW); //Get the minimum value of canvas width and height agl = data_arr[i].value * pi2 + startAgl; //End point c.strokeStyle = color_arr[i]; c.lineWidth = data_arr[i].value * min * 0.3; // Line thickness c.beginPath(); c.arc(cW / 2, cH / 2, min * 0.3, startAgl, agl, false); //Draw a circle c.stroke(); c.closePath(); startAgl = agl; //Draw a legend c.fillStyle = color_arr[i]; c.fillRect(cW * 0.8, 50 + 18 * i, 16, 16); c.fillText(data_arr[i].name, cW * 0.8 + 20, 62 + 18 * i); } }(2) Calling method:
let color = ['#0580F2', '#FAA732', '#E1575D', '#8B73CC', '#8CD123', '#4B53BA', '#429588']; let option = { color: color, data: [ { name: '20', value: '20' }, { name: '30', value: '30' }, { name: '40', value: '40' }, { name: '50', value: '50' }, { name: '60', value: '60' }, ] } drawCircle('myCanvas', option )The above is the entire content of this article. I hope it will be helpful to everyone’s study. I also hope everyone will support VeVb Wulin Network.