重新发送ajax请求，直到页面结束

Question

如何重新发送相同的ajax请求，直到页面结束时使用纯javascript（请不要使用框架）。按照我的代码：

xmlhttp=new XMLHttpRequest();
xmlhttp.open("POST","demo_post2.asp",true);
xmlhttp.setRequestHeader("Content-type","application/x-www-form-urlencoded");
xmlhttp.send("fname=Henry&lname=Ford");    
xmlhttp.onreadystatechange=function(){
if (xmlhttp.readyState==4 && xmlhttp.status==200){
  // resend the same request, until the close of the page 
}

Answer 1

我不知道你为什么要这样做，但是你走了。

// Reusing variable to keep garbage low.
var xhr;
// Recursive request.
function recursiveXHR () {
    xhr = new XMLHttpRequest();
    xhr.open('POST','demo_post2.asp',true);
    xhr.setRequestHeader('Content-type','application/x-www-form-urlencoded');
    // This is where the method is called again once the previous request is done.
    xhr.addEventListener('load', recursiveXHR, false);
    xhr.send('fname=Henry&lname=Ford');
}
// Initializing the recursive calling.
recursiveXHR();