JSFiddle - React, Tailwind, and code Playground

by yacan8

HTML

<canvas id="canvas"></canvas>

JavaScript

function draw() {
  var ctx = document.getElementById('canvas').getContext('2d');
  var lineCap = ['butt','round','square'];

  // 创建路径
  ctx.strokeStyle = '#09f';
  ctx.beginPath();
  ctx.moveTo(10,10);
  ctx.lineTo(140,10);
  ctx.moveTo(10,140);
  ctx.lineTo(140,140);
  ctx.stroke();

  // 画线条
  ctx.strokeStyle = 'black';
  for (var i=0;i<lineCap.length;i++){
    ctx.lineWidth = 15;
    ctx.lineCap = lineCap[i];
    ctx.beginPath();
    ctx.moveTo(25+i*50,10);
    ctx.lineTo(25+i*50,140);
    ctx.stroke();
  }
}
draw()