<!doctype html>
<html xmlns="http://www.w3.org/1999/xhtml">
    <head>
        <meta charset="utf-8">
        <title>轻松编程</title>
        <script type="text/javascript">
            function hello() {
                alert('hi');
            }
        </script>
    </head>
    <body onload="javascript:hello()">
        <p>添加一张图片，测试一下微信分享的效果。</p>
        <img src="food-newspaper.jpg" alt="漂亮的食物" width="658" height="658"></img>
        <p>这张图片应该作为微信分享内容的缩略图吧？</p>
    </body>
</html>

<!doctype html>
<html xmlns="http://www.w3.org/1999/xhtml">
    <head>
        <meta charset="utf-8">
        <title>轻松编程</title>
        <script type="text/javascript">
            function hello() {
                document.getElementById('greeting').innerText = 'Hello, world!';
            }
        </script>
    </head>
    <body onload="javascript:hello()">
        <p>添加一张图片，测试一下微信分享的效果。</p>
        <img src="food-newspaper.jpg" alt="漂亮的食物" width="658" height="658"></img>
        <p>这张图片应该作为微信分享内容的缩略图吧？</p>
        <div id="greeting"></div>
    </body>
</html>

Test modify div content in wechat.
Test modify div content in wechat.