The simplest way to disable a datalist component is to put a mask <div> layer on it. Please look at this code.
<div style="width:400px;height:250px;position:relative">
<ul class="easyui-datalist" title="Basic DataList" lines="true" fit="true" style="display:none">
<li value="AL">Alabama</li>
<li value="AK">Alaska</li>
<li value="AZ">Arizona</li>
<li value="AR">Arkansas</li>
<li value="CA">California</li>
<li value="CO">Colorado</li>
<li value="CT">Connecticut</li>
<li value="DE">Delaware</li>
<li value="FL">Florida</li>
<li value="GA">Georgia</li>
<li value="WI">Wisconsin</li>
<li value="WY">Wyoming</li>
</ul>
<div style="position:absolute;top:0;left:0;bottom:0;right:0;background:#000;opacity:0.1"></div>
</div>