// 使用原生js 封装ajax
// 兼容xhr对象
function createXHR(){if(typeof XMLHttpRequest != "undefined"){ // 非IE6浏览器return new XMLHttpRequest();}else if(typeof ActiveXObject != "undefined"){   // IE6浏览器var version = ["MSXML2.XMLHttp.6.0","MSXML2.XMLHttp.3.0","MSXML2.XMLHttp",];for(var i = 0; i < version.length; i++){try{return new ActiveXObject(version[i]);}catch(e){//跳过}}}else{throw new Error("您的系统或浏览器不支持XHR对象！");}
}
// 转义字符
function params(data){var arr = [];for(var i in data){arr.push(encodeURIComponent(i) + "=" + encodeURIComponent(data[i]));}return arr.join("&");
}
// 封装ajax
function ga_ajax(obj){var xhr = createXHR();obj.url = obj.url + "?rand=" + Math.random(); // 清除缓存obj.data = params(obj.data);      // 转义字符串if(obj.method === "get"){      // 判断使用的是否是get方式发送obj.url += obj.url.indexOf("?") == "-1" ? "?" + obj.data : "&" + obj.data;}// 异步if(obj.async === true){// 异步的时候需要触发onreadystatechange事件xhr.onreadystatechange = function(){// 执行完成if(xhr.readyState == 4){callBack();}}}xhr.open(obj.method,obj.url,obj.async);  // false是同步 true是异步 // "demo.php?rand="+Math.random()+"&name=ga&ga",if(obj.method === "post"){xhr.setRequestHeader("Content-Type","application/x-www-form-urlencoded");xhr.send(obj.data);}else{xhr.send(null);}// xhr.abort(); // 取消异步请求// 同步if(obj.async === false){callBack();}// 返回数据function callBack(){// 判断是否返回正确if(xhr.status == 200){obj.success(xhr.responseText);}else{obj.Error("获取数据失败，错误代号为："+xhr.status+"错误信息为："+xhr.statusText);}}
}var html = document.getElementsByTagName("html")[0];
html.onclick = function(){ga_ajax({"method" : "post","url" : "dem0o.php","data" : {"name" : "gaga","age" : 10000000,"num" : "12346&598"},"success" : function(data){alert(data);},"Error" : function(text){alert(text);},"async" : false});
}