1.首先为需要触发enter事件的控件中添加onkeydown事件:
支持onkeydown事件的标签为：
<a>, <acronym>, <address>, <area>, <b>, <bdo>, <big>, <blockquote>, <body>, <button>, <caption>, <cite>, <code>, <dd>, <del>, <dfn>, <div>, <dt>, <em>, <fieldset>, <form>, <h1> to <h6>, <hr>, <i>, <input>, <kbd>, <label>, <legend>, <li>, <map>, <object>, <ol>, <p>, <pre>, <q>, <samp>, <select>, <small>, <span>, <strong>, <sub>, <sup>, <table>, <tbody>, <td>, <textarea>, <tfoot>, <th>, <thead>, <tr>, <tt>, <ul>, <var> |
则，例如可以对table标签添加onkeydown事件。（此时在table中的标签用键盘输入时都会触发该事件）
<table onkeydown="keydown(event)"></table>