Regarding (count down) timer for application in asp.net c# - asp.net

Question

Hi
I have created online quiz. I have added Count-down timer,label for question & radiobuttonlist for answers and next button for next question. I have code for timer but this timer gets start again when i click next button as i want count down timer for whole questions(Quiz).
Count down timer code(Javascript) is as follows:
var hour=0; //specify hours for counter
var min= '<%= Session["timer"] %>'; // specify minutes
var second = '<%= Session["second"] %>'; // specify the seconds
var lab = 'cd'; // id of the entry on the page where the counter(for question) is to be inserted & cd is span id in aspx page where i am displaying countdown timer
function start()
{
displayCountdown(setCountdown(hour,min,second),lab);
}
loaded(lab,start);
var pageLoaded = 0;
window.onload = function() {pageLoaded = 1;}
function loaded(i,f)
{
if (document.getElementById && document.getElementById(i) != null)
f();
else if (!pageLoaded)
setTimeout('loaded(\''+i+'\','+f+')',100);
}
function setCountdown(hour,min,second)
{
if(hour>0)
min=min*hour*60;
c = setC(min,second);
return c;
}
function setC(min,second)
{
if(min>0)
second=min*60*second;
return Math.floor(second);
}
function displayCountdown(countdn,cd)
{
if (countdn < 0)
{
document.getElementById(cd).innerHTML = "Sorry, you are too late.";
__doPostBack('__Page');
}
else
{
var secs = countdn % 60;
if (secs < 10)
secs = '0'+secs;
var countdn1 = (countdn - secs) / 60;
var mins = countdn1 % 60;
if (mins < 10)
mins = '0'+mins;
countdn1 = (countdn1 - mins) / 60;
var hours = countdn1 % 24;
document.getElementById(cd).innerHTML = hours+' : '+mins+' : '+secs;
setTimeout('displayCountdown('+(countdn-1)+',\''+cd+'\');',999);
}
}

Answer 1

You must keep a reference on "present" time relatively of the "start" time and the duration of the quiz. So, you would substract "present" time from start time.
protected int HoursDuration {
get {
if (Session["HoursDuration"] == null) { Session["HoursDuration"] = 0; }
return Convert.ToInt32(Session["HoursDuration"]);
}
set { Session["HoursDuration"] = value; }
}
protected int MinutesDuration {
get {
if (Session["MinutesDuration"] == null) { Session["MinutesDuration"] = 0; }
return Convert.ToInt32(Session["MinutesDuration"]);
}
set { Session["MinutesDuration"] = value; }
}
protected int SecondsDuration {
get {
if (Session["SecondsDuration"] == null) { Session["SecondsDuration"] = 0; }
return Convert.ToInt32(Session["SecondsDuration"]);
}
set { Session["SecondsDuration"] = value; }
}
protected int HoursLeft {
get {
return (this.EndTime - this.BeginTime).Hours;
}
}
protected int MinutesLeft {
get {
return (this.EndTime - this.BeginTime).Minutes;
}
}
protected int SecondsLeft {
get {
return (this.EndTime - this.BeginTime).Seconds;
}
}
protected DateTime EndTime {
get {
if (Session["EndTime"] == null) { Session["EndTime"] = DateTime.Now; }
return Convert.ToDateTime(Session["EndTime"]);
}
set { ViewState["EndTime"] = value; }
}
protected DateTime BeginTime {
get {
if (Session["BeginTime"] == null) { Session["BeginTime"] = DateTime.Now; }
return Convert.ToDateTime(Session["BeginTime"]);
}
set { ViewState["BeginTime"] = value; }
}
protected override void OnInit(EventArgs e) {
this.BeginTime = DateTime.Now; // Present time
if (!IsPostBack) {
// The countdown
this.HoursDuration = 0;
this.MinutesDuration = 10;
this.SecondsDuration = 0;
// Only on !postback, you set up when it ends
this.EndTime = this.BeginTime.AddHours(this.HoursDuration)
.AddMinutes(this.MinutesDuration)
.AddSeconds(this.SecondsDuration);
}
base.OnInit(e);
}
Then, in you javascript, call the HoursLeft, MinutesLeft and secondeLeft. I think this should work.