一个jsonp的简单实例

 <script type="text/javascript">
     //添加<script>标签的方法
     function addScriptTag(src){
         var script = document.createElement('script');
         script.setAttribute("type","text/javascript");
         script.src = src;
         document.body.appendChild(script);
     }

     window.onload = function(){
         //搜索apple，将自定义的回调函数名result传入callback参数中
         addScriptTag("http://ajax.googleapis.com/ajax/services/search/web?v=1.0&q=apple&callback=result");

     }
     //自定义的回调函数result
     function result(data) {
         //我们就简单的获取apple搜索结果的第一条记录中url数据
         alert(data.responseData.results[0].unescapedUrl);
     }
 </script>

jquery中使用

 <script type="text/javascript" src="http://code.jquery.com/jquery-latest.js"></script>
 <script type="text/javascript">
    $.ajax({
         url:"http://localhost:20002/MyService.ashx?callback=?",
         dataType:"jsonp",
         jsonpCallback:"person",
         success:function(data){
             alert(data.name + " is a a" + data.sex);
         }
    });
 </script>

 <script type="text/javascript" src="http://code.jquery.com/jquery-latest.js"></script>
 <script type="text/javascript">
     $.getJSON("http://localhost:20002/MyService.ashx?callback=?",function(data){
         alert(data.name + " is a a" + data.sex);
     });
 </script>