根据userAgent判断打开网页的所在终端，以及浏览器

function _IsIOS() {

    var ua = navigator.userAgent.toLowerCase();

    if(ua.match(/iPhone\sOS/i) == "iphone os") {

        return true;

    } else {

        return false;

    }

}

function _IsAndroid() {

    var ua = navigator.userAgent.toLowerCase();

    if(ua.match(/Android/i) == "android") {

        return true;

    } else {

        return false;

    }

}

function is_PC() {

    var userAgentInfo = navigator.userAgent;

    var Agents = new Array("Android", "iPhone", "SymbianOS", "Windows Phone", "iPad", "iPod");

    var flag = true;

    for(var v = 0; v < Agents.length; v++) {

        if(userAgentInfo.indexOf(Agents[v]) > 0) {

            flag = false;

            break;

        }

    }

    return flag;

}

function is_weixin() {

    var ua = navigator.userAgent.toLowerCase();

    if(ua.match(/MicroMessenger/i) == "micromessenger") {

        return true;

    } else {

        return false;

    }

}

function is_weibo() {

    var userAgent = window.navigator.userAgent.toLowerCase();

    if(userAgent.indexOf("weibo") > -1) {

        return true;

    } else {

        return false;

    }

}

function is_qq() {
var userAgent = window.navigator.userAgent.toLowerCase();
if(userAgent.indexOf("mqqbrowser") > -1) {
return true;
} else {
return false;
}
}