您可以使用以下函数:

function callAjax(url, callback){
    var xmlhttp;
    // compatible with IE7+, Firefox, Chrome, Opera, Safari
    xmlhttp = new XMLHttpRequest();
    xmlhttp.onreadystatechange = function(){
        if (xmlhttp.readyState == 4 && xmlhttp.status == 200){
            callback(xmlhttp.responseText);
        }
    }
    xmlhttp.open("GET", url, true);
    xmlhttp.send();
}

你可以在这些链接上尝试类似的解决方案:

https://www.w3schools.com/xml/tryit.asp?filename=tryajax_first https://www.w3schools.com/xml/tryit.asp?filename=tryajax_callback

这可能会有帮助:

function doAjax(url, callback) {
    var xmlhttp = window.XMLHttpRequest ? new XMLHttpRequest() : new ActiveXObject("Microsoft.XMLHTTP");

    xmlhttp.onreadystatechange = function() {
        if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
            callback(xmlhttp.responseText);
        }
    }

    xmlhttp.open("GET", url, true);
    xmlhttp.send();
}

这里有一个非常好的纯javascript解决方案

/*create an XMLHttpRequest object*/

let GethttpRequest=function(){  
  let httpRequest=false;
  if(window.XMLHttpRequest){
    httpRequest   =new XMLHttpRequest();
    if(httpRequest.overrideMimeType){
    httpRequest.overrideMimeType('text/xml');
    }
  }else if(window.ActiveXObject){
    try{httpRequest   =new ActiveXObject("Msxml2.XMLHTTP");
  }catch(e){
      try{
        httpRequest   =new ActiveXObject("Microsoft.XMLHTTP");
      }catch(e){}
    }
  }
  if(!httpRequest){return 0;}
  return httpRequest;
}

  /*Defining a function to make the request every time when it is needed*/

  function MakeRequest(){

    let uriPost       ="myURL";
    let xhrPost       =GethttpRequest();
    let fdPost        =new FormData();
    let date          =new Date();

    /*data to be sent on server*/
    let data          = { 
                        "name"      :"name",
                        "lName"     :"lName",
                        "phone"     :"phone",
                        "key"       :"key",
                        "password"  :"date"
                      };

    let JSONdata =JSON.stringify(data);             
    fdPost.append("data",JSONdata);
    xhrPost.open("POST" ,uriPost, true);
    xhrPost.timeout = 9000;/*the time you need to quit the request if it is not completed*/
    xhrPost.onloadstart = function (){
      /*do something*/
    };
    xhrPost.onload      = function (){
      /*do something*/
    };
    xhrPost.onloadend   = function (){
      /*do something*/
    }
    xhrPost.onprogress  =function(){
      /*do something*/
    }

    xhrPost.onreadystatechange =function(){

      if(xhrPost.readyState < 4){

      }else if(xhrPost.readyState === 4){

        if(xhrPost.status === 200){

          /*request succesfull*/

        }else if(xhrPost.status !==200){

          /*request failled*/

        }

      }


   }
  xhrPost.ontimeout = function (e){
    /*you can stop the request*/
  }
  xhrPost.onerror = function (){
    /*you can try again the request*/
  };
  xhrPost.onabort = function (){
    /*you can try again the request*/
  };
  xhrPost.overrideMimeType("text/plain; charset=x-user-defined-binary");
  xhrPost.setRequestHeader("Content-disposition", "form-data");
  xhrPost.setRequestHeader("X-Requested-With","xmlhttprequest");
  xhrPost.send(fdPost);
}

/*PHP side
<?php
  //check if the variable $_POST["data"] exists isset() && !empty()
  $data        =$_POST["data"];
  $decodedData =json_decode($_POST["data"]);
  //show a single item from the form
  echo $decodedData->name;

?>
*/

/*Usage*/
MakeRequest();

var load_process = false;
function ajaxCall(param, response) {

 if (load_process == true) {
     return;
 }
 else
 { 
  if (param.async == undefined) {
     param.async = true;
 }
 if (param.async == false) {
         load_process = true;
     }
 var xhr;

 xhr = new XMLHttpRequest();

 if (param.type != "GET") {
     xhr.open(param.type, param.url, true);

     if (param.processData != undefined && param.processData == false && param.contentType != undefined && param.contentType == false) {
     }
     else if (param.contentType != undefined || param.contentType == true) {
         xhr.setRequestHeader('Content-Type', param.contentType);
     }
     else {
         xhr.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');
     }


 }
 else {
     xhr.open(param.type, param.url + "?" + obj_param(param.data));
 }

 xhr.onprogress = function (loadTime) {
     if (param.progress != undefined) {
         param.progress({ loaded: loadTime.loaded }, "success");
     }
 }
 xhr.ontimeout = function () {
     this.abort();
     param.success("timeout", "timeout");
     load_process = false;
 };

 xhr.onerror = function () {
     param.error(xhr.responseText, "error");
     load_process = false;
 };

 xhr.onload = function () {
    if (xhr.status === 200) {
         if (param.dataType != undefined && param.dataType == "json") {

             param.success(JSON.parse(xhr.responseText), "success");
         }
         else {
             param.success(JSON.stringify(xhr.responseText), "success");
         }
     }
     else if (xhr.status !== 200) {
         param.error(xhr.responseText, "error");

     }
     load_process = false;
 };
 if (param.data != null || param.data != undefined) {
     if (param.processData != undefined && param.processData == false && param.contentType != undefined && param.contentType == false) {
             xhr.send(param.data);

     }
     else {
             xhr.send(obj_param(param.data));

     }
 }
 else {
         xhr.send();

 }
 if (param.timeout != undefined) {
     xhr.timeout = param.timeout;
 }
 else
{
 xhr.timeout = 20000;
}
 this.abort = function (response) {

     if (XMLHttpRequest != null) {
         xhr.abort();
         load_process = false;
         if (response != undefined) {
             response({ status: "success" });
         }
     }

 }
 }
 }

function obj_param(obj) {
var parts = [];
for (var key in obj) {
    if (obj.hasOwnProperty(key)) {
        parts.push(encodeURIComponent(key) + '=' + encodeURIComponent(obj[key]));
    }
}
return parts.join('&');
}

我的ajax调用

  var my_ajax_call=ajaxCall({
    url: url,
    type: method,
    data: {data:value},
    dataType: 'json',
    async:false,//synchronous request. Default value is true 
    timeout:10000,//default timeout 20000
    progress:function(loadTime,status)
    {
    console.log(loadTime);
     },
    success: function (result, status) {
      console.log(result);
    },
      error :function(result,status)
    {
    console.log(result);
     }
      });

对于中止先前的请求

      my_ajax_call.abort(function(result){
       console.log(result);
       });

<html>
  <script>
    var xmlDoc = null ;

  function load() {
    if (typeof window.ActiveXObject != 'undefined' ) {
      xmlDoc = new ActiveXObject("Microsoft.XMLHTTP");
      xmlDoc.onreadystatechange = process ;
    }
    else {
      xmlDoc = new XMLHttpRequest();
      xmlDoc.onload = process ;
    }
    xmlDoc.open( "GET", "background.html", true );
    xmlDoc.send( null );
  }

  function process() {
    if ( xmlDoc.readyState != 4 ) return ;
    document.getElementById("output").value = xmlDoc.responseText ;
  }

  function empty() {
    document.getElementById("output").value = '<empty>' ;
  }
</script>

<body>
  <textarea id="output" cols='70' rows='40'><empty></textarea>
  <br></br>
  <button onclick="load()">Load</button> &nbsp;
  <button onclick="empty()">Clear</button>
</body>
</html>

这是一个没有JQuery的JSFiffle

http://jsfiddle.net/rimian/jurwre07/

function loadXMLDoc() {
    var xmlhttp = new XMLHttpRequest();
    var url = 'http://echo.jsontest.com/key/value/one/two';

    xmlhttp.onreadystatechange = function () {
        if (xmlhttp.readyState == XMLHttpRequest.DONE) {
            if (xmlhttp.status == 200) {
                document.getElementById("myDiv").innerHTML = xmlhttp.responseText;
            } else if (xmlhttp.status == 400) {
                console.log('There was an error 400');
            } else {
                console.log('something else other than 200 was returned');
            }
        }
    };

    xmlhttp.open("GET", url, true);
    xmlhttp.send();
};

loadXMLDoc();