AfterThreeYears/gist:bbb1e784930f5b285c1984280942c67d

## gistfile1.txt
<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <button id="button">下载</button>
  <script src="https://cdn.bootcss.com/FileSaver.js/2014-11-29/FileSaver.js"></script>
  <script>
    const img = new Image()
    img.onload = () => {
      // 画图片
      const canvas = document.createElement("canvas");
      const ctx = canvas.getContext('2d');
      canvas.width = img.width;
      canvas.height = img.height;
      ctx.drawImage(img, 0, 0);
      canvas.toBlob(function(blob) {
        console.log(blob);
        saveAs(blob, '下载');
        //  const newImg = document.createElement("img"),
        //  url = URL.createObjectURL(blob);

        // newImg.onload = function() {
        //   // no longer need to read the blob so it's revoked
        /通过一个链接下载文件/   URL.revokeObjectURL(url);
        // };

        // newImg.src = url;
        // document.body.appendChild(newImg);
      });
    }
    img.crossOrigin = 'anonymous';
    button.onclick = () => {
      img.src = 'https://kano.guahao.cn/0yh262685325?token=YTAzN2Y4MDhlZmE4OTE0NmQzNDFkZGY4ZTc2N2RjNzRfTUQ1COUSTOM&v=1.0'
    }
  </script>
</body>
</html>
	<!DOCTYPE html>
	<html lang="en">
	<head>
	<meta charset="UTF-8">
	<meta name="viewport" content="width=device-width, initial-scale=1.0">
	<title>Document</title>
	</head>
	<body>
	<button id="button">下载</button>
	<script src="https://cdn.bootcss.com/FileSaver.js/2014-11-29/FileSaver.js"></script>
	<script>
	const img = new Image()
	img.onload = () => {
	// 画图片
	const canvas = document.createElement("canvas");
	const ctx = canvas.getContext('2d');
	canvas.width = img.width;
	canvas.height = img.height;
	ctx.drawImage(img, 0, 0);
	canvas.toBlob(function(blob) {
	console.log(blob);
	saveAs(blob, '下载');
	// const newImg = document.createElement("img"),
	// url = URL.createObjectURL(blob);

	// newImg.onload = function() {
	// // no longer need to read the blob so it's revoked
	/通过一个链接下载文件/ URL.revokeObjectURL(url);
	// };

	// newImg.src = url;
	// document.body.appendChild(newImg);
	});
	}
	img.crossOrigin = 'anonymous';
	button.onclick = () => {
	img.src = 'https://kano.guahao.cn/0yh262685325?token=YTAzN2Y4MDhlZmE4OTE0NmQzNDFkZGY4ZTc2N2RjNzRfTUQ1COUSTOM&v=1.0'
	}
	</script>
	</body>
	</html>