AJAX为canceled

https://stackoverflow.com/questions/12009423/what-does-status-canceled-for-a-resource-mean-in-chrome-developer-tools

status=canceled may happen also on ajax requests on JavaScript events:

<script>
  $("#call_ajax").on("click", function(event){
     $.ajax({
        ...    
     });
  });
</script>

<button id="call_ajax">call</button> 

The event successfully sends the request, but is is canceled then (but processed by the server). The reason is, the elements submit forms on click events, no matter if you make any ajax requests on the same click event.

To prevent request from being cancelled, JavaScript event.preventDefault(); have to be called:

<script>
  $("#call_ajax").on("click", function(event){
     event.preventDefault();
     $.ajax({
        ...    
     });
  });
</script>