Cross-domain requests: jQuery's ajax jsonp usage solution-JS Tutorial-php.cn

Cross-domain requests: jQuery's ajax jsonp usage solution

高洛峰

Release： 2017-01-09 10:50:01

Original

1341 people have browsed it

Directly executing the error method prompts an error - ajax jsonp has not been used before, and the understanding of it is similar to that of ordinary ajax requests, and there is no in-depth understanding of it; this error occurred, after debugging several times (check the background code and js part of the property settings) still doesn't work, which makes me feel very surprised and puzzled. Therefore, I decided to carefully study the use of ajax jsonp, and share the learning experience of the final successful test with everyone!
First, post the code that can be successfully executed:
(page part)

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 
<html xmlns="http://www.w3.org/1999/xhtml" > 
<head> 
<title>Untitled Page</title> 
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"></script> 
<script type="text/javascript"> 
jQuery(document).ready(function(){ 
$.ajax({ 
type : "get", 
async:false, 
url : "ajax.ashx", 
dataType : "jsonp", 
jsonp: "callbackparam",//传递给请求处理程序或页面的，用以获得jsonp回调函数名的参数名(默认为:callback) 
jsonpCallback:"success_jsonpCallback",//自定义的jsonp回调函数名称，默认为jQuery自动生成的随机函数名 
success : function(json){ 
alert(json); 
alert(json[0].name); 
}, 
error:function(){ 
alert(&#39;fail&#39;); 
} 
}); 
var a="firstName Brett"; 
alert(a); 
}); 
</script> 
</head> 
<body> 
</body> 
</html>

Copy after login

(Handler part)

<%@ WebHandler Language="C#" Class="ajax" %> 
using System; 
using System.Web; 
public class ajax : IHttpHandler { 
public void ProcessRequest (HttpContext context) { 
context.Response.ContentType = "text/plain"; 
string callbackFunName = context.Request["callbackparam"]; 
context.Response.Write(callbackFunName + "([ { name:\"John\"} ] )"); 
} 
public bool IsReusable { 
get { 
return false; 
} 
} 
}

Copy after login

(Request packet capture screenshot)

跨域请求之jQuery的ajax jsonp的使用解惑

function success_jsonpCallback(data) 
{ 
success(data); 
}

Copy after login

More cross-domain requests Please pay attention to the PHP Chinese website for related articles on the use of jQuery's ajax jsonp!