项目积累--ajax.js封装

js 代码

//////////////////ajax封装

var req;
var xmlDoc,xmlHttpRequest;
var ajaxExcetpion;
///////////调用的URL（以GET方式组装的参数)，回调方法callback
///////////返回:成功返回true,失败返回false;
function ajaxCallByGet(url,callback,win_self)
{
if (window.XMLHttpRequest) {
                win_self.req = new XMLHttpRequest();
                    if (req.overrideMimeType){
                    req.overrideMimeType('text/xml');
                        }
         } else if (window.ActiveXObject) {
            if (xmlHttpRequest) {
              win_self.req= new ActiveXObject(xmlHttpRequest);
            }else {
                   var versions = ["Msxml2.XMLHTTP.7.0", "Msxml2.XMLHTTP.6.0", "Msxml2.XMLHTTP.5.0", "Msxml2.XMLHTTP.4.0", "MSXML2.XMLHTTP.3.0", "MSXML2.XMLHTTP","MSXML.XMLHTTP",
                        "Microsoft.XMLHTTP"];
               for (var i = 0; i < versions.length ; i++) {
                 try {
                     win_self.req = new ActiveXObject(versions[i]);
                     if (win_self.req) {
                        xmlHttpRequest = versions[i];
                        ajaxExcetpion = null;
                        break;
                    }
                }
                catch (objException) {
                    ajaxExcetpion = objException;
                } ;
            }
            ;
        }
    }

    if(ajaxExcetpion){
      return false;
    }
    if(req){

         req.open("GET", url, true);
         req.onreadystatechange = callback;
         req.send(null);
    }
     return true;
}


/*
 * Returns an new XMLHttpRequest object, or false if the browser
 * doesn't support it
 */
function newXMLHttpRequest() {

    var xmlreq = false;

    if (window.XMLHttpRequest) {
        xmlreq = new XMLHttpRequest();
        if (xmlreq.overrideMimeType){
            xmlreq.overrideMimeType('text/xml');
        }
    } else if (window.ActiveXObject) {
        if (xmlHttpRequest) {
            xmlreq= new ActiveXObject(xmlHttpRequest);
        }else {
            var versions = ["MSXML.XMLHTTP",
                        "Microsoft.XMLHTTP","Msxml2.XMLHTTP.7.0", "Msxml2.XMLHTTP.6.0", "Msxml2.XMLHTTP.5.0", "Msxml2.XMLHTTP.4.0", "MSXML2.XMLHTTP.3.0", "MSXML2.XMLHTTP"];
            for (var i = 0; i < versions.length ; i++) {
                try {
                    xmlreq = new ActiveXObject(versions[i]);
                    if (xmlreq) {
                        xmlHttpRequest = versions[i];
                        ajaxExcetpion = null;
                        break;
                    }
                }
                catch (objException) {
                    ajaxExcetpion = objException;
                }

            }

        }
    }

return xmlreq;
}


    /*
    * Returns a function that waits for the specified XMLHttpRequest
    * to complete, then passes it XML response to the given handler function.
  * req - The XMLHttpRequest whose state is changing
  * responseXmlHandler - Function to pass the XML response to
  */
 function getReadyStateHandler(req, responseXmlHandler) {

   // Return an anonymous function that listens to the XMLHttpRequest instance
   return function () {

     // If the request's status is "complete"
     if (req.readyState == 4) {

       // Check that we received a successful response from the server
       if (req.status == 200) {

         // Pass the XML payload of the response to the handler function.
         responseXmlHandler(req);

       } else {

         // An HTTP problem has occurred
         alert("HTTP error "+req.status+": "+req.statusText);
       }
     }
   }
 }


function test()
{
  alert("test");
}