判断当前设备是PC、Android或者iOS

var u = navigator.userAgent;
var isAndroid = u.indexOf('Android') > -1 || u.indexOf('Adr') > -1; //android终端
var isiOS = !!u.match(/\(i[^;]+;( U;)? CPU.+Mac OS X/); //ios终端
var isPc = function IsPC() {//是否是PC

    var Agents = ["Android", "iPhone",
        "SymbianOS", "Windows Phone",
        "iPad", "iPod"];
    var isPC = true;
    for (var v = 0; v < Agents.length; v++) {
        if (userAgentInfo.indexOf(Agents[v]) > 0) {
            isPC = false;
            break;
        }
    }
    return isPC;
};