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Online Exam in C# ASP NET

, 13 Sep 2010 CPOL
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Online Examination Project with CountDown Timer


Most of us have come across Examination / Quiz projects. The important aspects of those projects is to have a timer that runs through the entire duration of the exam, having the timer running without reset by postbacks is the main concern of this article.


The idea is to keep the value of the timer in view state and to supply the same on postback so that the timer will keep running from its previous value.

Using the Script

Understanding the script used here is not a big deal I guess, and am leaving it with a little explanation, go through the attachment for better understanding,

Timer is initiated in the page PreRender event, supplying the StartValue, Timerinterval and the clientId of the output element.

When the timer is started for the first timer, it is supplied with the duration of the examination say it is 30 min, and assume that the candidate spent 2 mins on a question and the postback occurs on 28 min, this value is kept in the view state and the same is used to start the timer again on the page PreRender event:

function myTimer(startVal,interval,outputId, dataField)
this.value = startVal;
this.OutputCntrl = document.getElementById(outputId);
this.currentTimeOut = null;
this.interval = interval;

myTimer.prototype.Seconds = function(value){
var hoursMillSecs = (this.Hours(value)*3600000)
var minutesMillSecs = (this.Minutes(value)*60000)
var total = (hoursMillSecs + minutesMillSecs)
var ans = Math.floor(((this.value - total)%60000)/1000);

this.OutputCntrl.innerHTML = this.Hours(current) + ':' + this.Minutes(current) 
+ ':' +  this.Seconds(current);

Keeping the Value in ViewState

You have to register the scrip with RegisterStartupScript in the codebehind file that supplies the view state value to the script and keeps the timer running.

Timer is initiated in PreRender event and the start value of the timer is requested from the view state and supplied to the timer, and this value changes on each postback as the exam is on progress.

void Page_PreRender(object sender, EventArgs e)
      StringBuilder bldr = new StringBuilder();
      bldr.AppendFormat("var Timer = new myTimer({0},{1},'{2}','timerData');",
          this.timerStartValue, this.TimerInterval, this.lblTimerCount.ClientID);

      ClientScript.RegisterStartupScript(this.GetType(), "TimerScript",
                                    bldr.ToString(), true);

      ClientScript.RegisterHiddenField("timerData", timerStartValue.ToString());

// Gets or Sets the Timer Value to the ViewState
private Int32 TimerInterval
    object o = ViewState["timerInterval"];
    if (o != null) { return Int32.Parse(o.ToString()); }
    return 50;
    ViewState["timerInterval"] = value; 

Hope this will be a help to start your project. The attachment is prepared as a template that you can use for your project and can extend to meet your requirements.


  • 13th September, 2010: Initial post


This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


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Comments and Discussions

QuestionNo Database In The App Data Folder Pinmemberobaid ahmed(gleam)27-Mar-15 15:58 
Questionerror PinmemberAnirbanM 216-Jan-15 23:43 
GeneralMy vote of 4 PinmemberMember 1065735615-Jun-14 6:46 
GeneralMy vote of 4 PinmemberRajesh198897-Apr-14 21:00 
QuestionProblem with timer Pinmemberdownloadsrk26-May-13 20:17 
AnswerRe: Problem with timer PinmemberVallarasuS26-May-13 20:26 
QuestionType or namespace ConnectToDb could not be found . Pinmemberaksrup17-May-13 4:45 
AnswerRe: Type or namespace ConnectToDb could not be found . PinmemberVallarasuS19-May-13 21:02 
GeneralRe: Type or namespace ConnectToDb could not be found . Pinmemberaksrup20-May-13 1:19 
QuestionMaster Pages Pinmemberpatiya25-Oct-12 2:04 
AnswerRe: Master Pages PinmemberVallarasuS25-Oct-12 6:21 
QuestionDatabase download Pinmemberrahuljains18-Sep-12 21:31 
AnswerRe: Database download PinmemberDannoman123415-Apr-14 3:32 
QuestionTimer is not working when i added the scriptmanager tag in aspx page because of using ajax PinmemberK.Mohamed Sujaludeen7-Sep-12 23:41 
QuestionRe: Timer is not working when i added the scriptmanager tag in aspx page because of using ajax Pinmembervsanju6-Jun-14 0:18 
QuestionNot find file solution? Pinmemberk56flex23-Aug-12 19:01 
AnswerRe: Not find file solution? PinmemberVallarasuS23-Aug-12 19:28 
Web applications / Web Projects can be opened with out solution file.

Open up Visual Studio >> File >> Open >> Web Site >> .. and select the downloaded folder in browser dialog.

Regards Vallarasu S |

QuestionVB Version of the timer Pinmemberpatiya17-Aug-12 6:58 
AnswerRe: VB Version of the timer PinmemberVallarasuS20-Aug-12 20:45 PinmemberMember 869876723-May-12 19:11 
Questiondatabase for quiz Pinmembermbjino15-Apr-12 21:27 
AnswerRe: database for quiz Pinmembermbjino15-Apr-12 21:29 
GeneralRe: database for quiz PinmemberVallarasuS15-Apr-12 23:47 
GeneralRe: database for quiz Pinmembermbjino16-Apr-12 4:01 
GeneralRe: database for quiz Pinmembertesstaco1-May-12 9:07 

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