JSONP跨域数据获取原理与实现详解

<!DOCTYPE html>
<html>
<head>
 <title></title>
</head>
<body>
<script type="text/javascript">
 function jsonp(data){
  console.log(username)
 }
</script>
<script type="text/javascript" src="jquery-1.8.3.min.js">
</script>
<script type="text/javascript">
 $(document).ready(function(){
  var url = "http://www.example.com/jsonp.php?callback=jsonp";
  var script = $('<script><\/script>');
  script.attr("src",url);
  $("body").append(script);
 });
</script>
</body>
</html>

<?php

$data = {'name': '张三'};
$callback = $_GET['callback'];
echo $callback."(".json_encode($data).")";

?php>

jsonp（{
 name:'niuni
}）

<script>
 function showData (data) {
  console.info(data);
 }
 $(document).ready(function () {
  $("#btn").click(function () {
   $.ajax({
    url: "http://www.example.comjsonp",
    type: "GET",
    dataType: "jsonp",// 返回数据类型
    jsonpCallback: "showData",//回调函数
    // 获取数据成功就执行success函数
    success: function (data) {
     console.info("data");
    }
   });
  });
 });
</script>