下面是我使用Fetch API和async函数的方法

<div class="js-component" data-name="header" data-ext="html"></div>
<div class="js-component" data-name="footer" data-ext="html"></div>

<script>
    const components = document.querySelectorAll('.js-component')

    const loadComponent = async c => {
        const { name, ext } = c.dataset
        const response = await fetch(`${name}.${ext}`)
        const html = await response.text()
        c.innerHTML = html
    }

    [...components].forEach(loadComponent)
</script>

作为一种替代方法，如果你可以访问服务器上的。htaccess文件，你可以添加一个简单的指令，允许php在以。html扩展名结尾的文件上被解释。

RemoveHandler .html
AddType application/x-httpd-php .php .html

现在你可以使用一个简单的php脚本来包含其他文件，比如:

<?php include('b.html'); ?>

下面是我使用Fetch API和async函数的方法

<div class="js-component" data-name="header" data-ext="html"></div>
<div class="js-component" data-name="footer" data-ext="html"></div>

<script>
    const components = document.querySelectorAll('.js-component')

    const loadComponent = async c => {
        const { name, ext } = c.dataset
        const response = await fetch(`${name}.${ext}`)
        const html = await response.text()
        c.innerHTML = html
    }

    [...components].forEach(loadComponent)
</script>

html5rocks.com has a very good tutorial on this stuff, and this might be a little late, but I myself didn't know this existed. w3schools also has a way to do this using their new library called w3.js. The thing is, this requires the use of a web server and and HTTPRequest object. You can't actually load these locally and test them on your machine. What you can do though, is use polyfills provided on the html5rocks link at the top, or follow their tutorial. With a little JS magic, you can do something like this:

 var link = document.createElement('link');
 if('import' in link){
     //Run import code
     link.setAttribute('rel','import');
     link.setAttribute('href',importPath);
     document.getElementsByTagName('head')[0].appendChild(link);
     //Create a phantom element to append the import document text to
     link = document.querySelector('link[rel="import"]');
     var docText = document.createElement('div');
     docText.innerHTML = link.import;
     element.appendChild(docText.cloneNode(true));
 } else {
     //Imports aren't supported, so call polyfill
     importPolyfill(importPath);
 }

This will make the link (Can change to be the wanted link element if already set), set the import (unless you already have it), and then append it. It will then from there take that and parse the file in HTML, and then append it to the desired element under a div. This can all be changed to fit your needs from the appending element to the link you are using. I hope this helped, it may irrelevant now if newer, faster ways have come out without using libraries and frameworks such as jQuery or W3.js.

UPDATE:这将抛出一个错误，表示本地导入已被CORS策略阻塞。可能需要访问深层网络才能使用它，因为深层网络的特性。(意思是没有实际用途)

不需要脚本。不需要做任何花哨的东西服务器端(尽管这可能是一个更好的选择)

<iframe src="/path/to/file.html" seamless></iframe>

由于旧的浏览器不支持无缝，你应该添加一些css来修复它:

iframe[seamless] {
    border: none;
}

请记住，对于不支持无缝链接的浏览器，如果您单击iframe中的链接，它将使框架指向该url，而不是整个窗口。一种解决方法是让所有链接都有target="_parent"，尽管浏览器的支持是“足够好”。

这对我很有帮助。为了将一个html代码块从b.html添加到a.html，这应该放在a.html的head标签中:

<script src="https://code.jquery.com/jquery-1.10.2.js"></script>

然后在body标签中，一个容器用一个唯一的id和一个javascript块来加载b.html到容器中，如下所示:

<div id="b-placeholder">

</div>

<script>
$(function(){
  $("#b-placeholder").load("b.html");
});
</script>