获取数据URL

代码运行

<!DOCTYPE HTML>
<html>
  <head>
    <title>获取数据URL</title>
    <style>
      body {
        margin: 0px;
        padding: 0px;
      }
    </style>
  </head>
  <body>
    <canvas id="myCanvas" width="578" height="200"></canvas>
    <script>
      var canvas = document.getElementById('myCanvas');
      var context = canvas.getContext('2d');

// draw cloud
      context.beginPath();
      context.moveTo(170, 80);
      context.bezierCurveTo(130, 100, 130, 150, 230, 150);
      context.bezierCurveTo(250, 180, 320, 180, 340, 150);
      context.bezierCurveTo(420, 150, 420, 120, 390, 100);
      context.bezierCurveTo(430, 40, 370, 30, 340, 50);
      context.bezierCurveTo(320, 5, 250, 20, 250, 50);
      context.bezierCurveTo(200, 5, 150, 20, 170, 80);
      context.closePath();
      context.lineWidth = 5;
      context.fillStyle = '#8ED6FF';
      context.fill();
      context.strokeStyle = '#0000ff';
      context.stroke();

// save canvas image as data url (png format by default)
      var dataURL = canvas.toDataURL();
    </script>
 </body>
</html>