如何在特定时间后自动运行Ajax请求？

Question

I have an Ajax function (ajaxRequest) that I want to run automatically after some specific time (say 5 sec) without any user-prompt or warning . How can i do this? (I looked in the following links but found no solution )

jQuery: How to make an AJAX request and continue without waiting for request to complete?

How do I run ajax request in background continuously?

How to run ajax call in background after some particulate time?

How to run execute page in background using ajax?

//My Code
//ajaxRequest Script..

<script type="text/javascript">
function ajaxRequest(map){

var xmlhttp = new XMLHttpRequest();
xmlhttp.open("GET", 'json_data.php', true);

xmlhttp.onreadystatechange = function() {
if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
    var myArr = JSON.parse(xmlhttp.responseText);
    setMarkers(map,myArr);
}
};
xmlhttp.send(null);
}
</script>

<script>
function myMap() {
var mapCanvas = document.getElementById("map");
var myCenter = new google.maps.LatLng(51.508742,-0.120850);
var lat=51.508742;
var lng=-0.140850;
var mapOptions = {center: myCenter, zoom: 5};
var map = new google.maps.Map(mapCanvas,mapOptions);

ajaxRequest(map);                                   //Called ajaxRequest

}
</script>

Answer 1

Hello this is solution for the automatically send the ajax request

Just put your function like this.

function myMap() {
var mapCanvas = document.getElementById("map");
var myCenter = new google.maps.LatLng(51.508742,-0.120850);
var lat=51.508742;
var lng=-0.140850;
var mapOptions = {center: myCenter, zoom: 5};
var map = new google.maps.Map(mapCanvas,mapOptions);                     
setInterval(function()
    {
      ajaxRequest(map);
    }, 5000);
}