jQuery post respond with readyState:0, status:0

all. I am using a jquery version 1.6.2. I do a ajax call like this:

  var jqxhr = $j.post(myPHP, function() {
          alert("success");
        })
        .success(function() { alert("second success"); })
        .error(function(data) { alert(JSON.开发者_开发技巧stringify(data)); })
        .complete(function() { alert("complete"); });

The script, run, and show error, than, complete. Some people may thing that...myPHP have some problem, but the myPHP is always show:

{"sayHi":"hihi"}

So, I go to firebugs to check whether the link have any problem, when I called..: It show me the POST url with status 200, which is ok. Also, I can see the respond via firebugs.... But the question is ....why the jquery so me have a error...: And here is the error msg:

{"readyState":0,"responseText":"","status":0,"statusText":"error"}

For me this problem was caused by a cross-domain issue. So I had a local html file (c:\test.html) and tried to get data from a server (localhost/servlet). When putting html on the server - the problem was gone.

If the browser switches the web page while an XHR request is still in progress (the user clicked a link, the back button, …), this XHR request will be cancelled with exactly your error.

Have a look at the following blog post, where the issue is explained in depth: http://bartwullems.blogspot.de/2012/02/ajax-request-returns-status-0.html

You forgot to tell jQuery that the server is returning JSON:

   var jqxhr = $j.post(myPHP, function() {
           alert("success");
         }, "json") // here
        .success(function() { alert("second success"); })
        .error(function(data) { alert(JSON.stringify(data)); })
        .complete(function() { alert("complete"); });

In my case, it was not due to Cross domain. I was not using e.PreventDefault(). See here