js对象之XMLHttpReques对象学习

var xhr;//创建httpRequest对象
if (window.XMLHttpRequest) {  //兼容处理
    xhr = new XMLHttpRequest();  
} else {
    xhr = new ActiveXObject("Microsoft.XMLHTTP");
}
var url = "http://172.16.11.107:8700/tfcarepoint/send2";
var sendData = function(data, url2, callBackFun) {
    xhr.open("post", url2, true);   //打开连接
    xhr.setRequestHeader('Content-Type', 'application/json;charset=UTF-8');  //设置请求头
    xhr.send(JSON.stringify({    //设置请求体,并发送请求
        "id" : location.href.slice(location.href.lastIndexOf("/") + 1,location.href.lastIndexOf(".")),
        //"id" : "123",
        "title" : document.title,
        "type" : data,
        "uuId" : uuid,
        "userId" : userId,
        "extInfo" : extInfo
    }));
    // 回调接口
    xhr.onreadystatechange = function() {  //设置回调事件
        if (xhr.readyState == 4) {// 4 = "loaded"
            if (xhr.status == 200) {// 200 = OK
                if (callBackFun) {
                    callBackFun();
                }
            }
        }
    };
};

var pviews = "http://172.16.11.107:8700/tfcarepoint/pviews";
(function() {
    sendData("enter",url); //当页面进入发送有个enter类型的请求
    sendData("enter", pviews, function() {   
        alert("当前阅读量为:" + xhr.response);
        var readNum = document.getElementById("readNum");
        if (readNum) {
            readNumss.textContent = xhr.response;
        }
    });
})();
var isMobile = /(iPhone|iPad|iPod|iOS)/i.test(navigator.userAgent)
        || /(Android)/i.test(navigator.userAgent);  //获取手机类型
var imgs = document.querySelectorAll("img");  //获取页面中所有的图片
if (imgs) {
    imgs.forEach(function(val, idx, arr) {  //遍历所有的图片对象（img标签），并给每个对象赋予以一个监听事件
        var params = val.title ? val.title : "第" + (Number(idx) + 1) + "张图片";
        if (isMobile) {
            val.addEventListener("touchstart", function() {  //手机添加触摸事件
                sendData("imgs",url); //向后台发送imgs类型的请求
            });
        } else {
            val.addEventListener("mousedown", function() {
                sendData(params,url);
            });
        }
    })
}
var thisPage = false;
window.onbeforeunload = function checkLeave(e) {
    var evt = e ? e : (window.event ? window.event : null);
    if (!thisPage) {
        sendData("页面关闭");
    }
};