样例如下：
<!DOCTYPE html>
<html xmlns="https://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>等值线的生成</title>
<link href="/go.html?url=Script/leaflet/leaflet.css" rel="stylesheet" />
<style><!DOCTYPE html>
<html xmlns="https:
