设置背景图像为垂直方向重复 - 在线编辑器

          <!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>蜜蜂教程(mifengjc.com)</title>
  <style type="text/css">
    body {
      background: #f3f3f3 url("/examples/img_tree.png");
    }
  </style>
  <script>
    function displayResult() {
      document.body.style.backgroundRepeat = "repeat-y";
    }
  </script>
</head>
<body>

  <button type="button" onclick="displayResult()">垂直重复背景图像</button>
  <br>
  <h1>Hello World!</h1>
  <p>这是一个段落</p>

</body>
</html>
        