使用cookie

// 写字段到cookie
setCookie(cname, cvalue, exdays) {
    var d = new Date();
    d.setTime(d.getTime() + ( 30 * 60 * 1000));
    var expires = "expires=" + d.toUTCString();
    document.cookie = cname + "=" + cvalue + "; " + expires + ";path=/";
},
// 读cookie
getCookie(cname) {
    var name = cname + "=";
    var ca = document.cookie.split(';');
    for (var i = 0; i < ca.length; i++) {
        var c = ca[i];
        while (c.charAt(0) == ' ') c = c.substring(1);
            if (c.indexOf(name) == 0) return c.substring(name.length, c.length);
        }
        return "";
},
// 清除cookie(expires设置为当前时间之前即可清除)
removeCookie(cname) {
    var d = new Date();
    d.setTime(d.getTime() - ( 24 * 60 * 60 * 1000));
    var expires = "expires=" + d.toUTCString();
    document.cookie = cname + "=; " + expires + ";path=/";
},