发送验证码，倒计时60s

点击发送验证码，按钮进入60s倒计时，用cookie记录60s。

//发送验证码
function sendCode(obj){
    var phone = $("#phone").val();
    var result = isPhoneNum();
    if(result){
        doPostBack('？member/sendsms/',backFunc1,{"phone":phone});
        addCookie("secondsremained",60,60);//添加cookie记录,有效时间60s
        settime(obj);//开始倒计时
    }
}
// 创建cookie
var addCookie = function (name, value, time) {
    let d = new Date();
    d.setTime(d.getTime() + (8*3600*1000) + (time*1000))
//这里获取的时间是GMT格式，比北京时间晚8个小时，需要+8小时
    var expires = "expires="+d.toGMTString();  
    //设置cookie的名称、值、失效时间
     document.cookie = name + "=" + value + "; " + expires;
}
// 获取cookie
function getCookieValue(cname)
{
  var name = cname + "=";
  var ca = document.cookie.split(';');
  for(var i=0; i<ca.length; i++) 
  {
    var c = ca[i].trim();
    if (c.indexOf(name)==0) return c.substring(name.length,c.length);
  }
  return "";
}
//将手机利用ajax提交到后台的发短信接口
function doPostBack(url,backFunc,queryParam) {
    $.ajax({
        async : false,
        cache : false,
        type : 'POST',
        url : url,// 请求的action路径
        data:queryParam,
        success: function (response, status) {
           console.log(response);
           console.log(status);
        },
        error: function (xhr, status, error) {
           console.log(error);
           console.log(xhr);
           console.log(status);
           backFunc
        }
    });
}
function backFunc1(data){
    console.log(data);
    var d = $.parseJSON(data);
    if(!d.success){
        alert(d.msg);
    }else{//返回验证码
        alert("模拟验证码:"+d.msg);
        $("#code").val(d.msg);
    }
}
//开始倒计时
var countdown;
function settime(obj) { 
    countdown=getCookieValue("secondsremained");
    if (countdown == 0) { 
        obj.removeAttr("disabled");  
        obj.removeClass('disabled')
        obj.text("获取验证码"); 
        return;
    } else { 
        obj.attr("disabled", true); 
        obj.addClass('disabled')
        obj.text("重新发送(" + countdown + ")"); 
        // console.log(obj.text("重新发送(" + countdown + ")"));
        countdown--;

        document.cookie="secondsremained="+countdown+";";
    } 
    setTimeout(function() { settime(obj) },1000) //每1000毫秒执行一次
} 
//校验手机号是否合法
function isPhoneNum(){
    var phonenum = $("#phone").val();
    var myreg = /^(((13[0-9]{1})|(15[0-9]{1})|(18[0-9]{1}))+\d{8})$/; 
    if(!myreg.test(phonenum)){ 
        $("#phone").focus()
        return false; 
    }else{
        return true;
    }
}