原生Ajax總結

標籤：ajax

HTTP協議

傳統的請求和Ajax請求
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Ajax定義

Asynchronous JavaScript and XML. Ajax非同步，JavaScript程式希望與伺服器直接通訊而不需要重新載入頁面。

Ajax基本流程

1.建立請求對象

function requestObject(){            if(window.XMLHttpRequest){                return new XMLHttpRequest();            }else if{                return new ActiveXObject(‘Mxsml2.XMLHTTP‘);            }else{                throw new Error("Could not create HTTP request object.");            }        }

2.建立請求
var request=requestObject();
request.open("GET","data.txt",true);

3.發送請求

request.send(null);

4.處理請求(XML和JSON兩種格式)

request.onreadystatechange=function(){            if(request.readyState==4){                console.log(request.status+":"+request.statusText);            }        }

原生Ajax總結