ajax原理笔记
2018-05-11 本文已影响5人
一枚程序猿
function AJAX() {
var xhr = null;
if(window.XMLHttpRequest) {
xhr = new XMLHttpRequest();
} else {
try{
xhr = new ActiveXObject('Microsoft.XMLHttp');
}catch(e){
xhr = new ActiveXObject('msxml2.xmlhttp');
}
}
//get请求
this.get = function(url,success,fail){
xhr.open("GET", url,true);
xhr.onreadystatechange=function(){
if(xhr.readyState==4) {
if(xhr.status==200) {
var txt = xhr.responseText;
txt = JSON.parse(txt);
success(txt);
} else {
if(fail) {
fail(xhr.status);
}
}
}
};
xhr.send(null);
};
//post请求
this.post = function (url,param,success,fail) {
xhr.open("POST", url,true);
xhr.onreadystatechange=function(){
if(xhr.readyState==4) {
if(xhr.status==200) {
var txt = xhr.responseText;
txt = JSON.parse(txt);
success(txt);
} else {
if(fail) {
fail(xhr.status);
}
}
}
};
xhr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
xhr.send(param);
};
}
//使用
var ajax = new AJAX();
ajax.get("test.json",
function(data){
//成功回调
},function(data){
//失败回调
});
