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Online Exam in C# ASP NET

, 13 Sep 2010 CPOL 139.4K 28.9K 30
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Online Examination Project with CountDown Timer

Introduction

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.

Background

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 PreRenderevent, supplying the StartValue, Timerintervaland the clientIdof 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 PreRenderevent:

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 RegisterStartupScriptin the codebehind file that supplies the view state value to the script and keeps the timer running.

Timer is initiated in PreRenderevent 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);
        
      bldr.Append("Timer.go()");

      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
{
  get
  {
    object o = ViewState["timerInterval"];
    if (o != null) { return Int32.Parse(o.ToString()); }
    return 50;
  }
  set
  {
    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.

History

  • 13th September, 2010: Initial post

License

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

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About the Author

VallarasuS
Software Developer
India India
I code, learn, listen, and some day in a near future be a proud farmer.

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Comments and Discussions

 
GeneralRe: Timer Pin
Member 994730327-Mar-13 17:32
memberMember 994730327-Mar-13 17:32 
QuestionDATA base Pin
Rajeshkrathor28-Dec-11 19:40
memberRajeshkrathor28-Dec-11 19:40 
AnswerRe: DATA base Pin
VallarasuS29-Dec-11 15:15
memberVallarasuS29-Dec-11 15:15 
GeneralMy vote of 4 Pin
kitupadma30-Oct-11 19:43
memberkitupadma30-Oct-11 19:43 
GeneralRe: My vote of 4 Pin
vallarasus17-Nov-11 4:18
membervallarasus17-Nov-11 4:18 
QuestionExam Questions in a SQLDB Pin
jpiscitelli20-Oct-11 4:09
memberjpiscitelli20-Oct-11 4:09 
AnswerRe: Exam Questions in a SQLDB Pin
vallarasus20-Oct-11 6:53
membervallarasus20-Oct-11 6:53 
GeneralRe: Exam Questions in a SQLDB Pin
jpiscitelli21-Oct-11 2:38
memberjpiscitelli21-Oct-11 2:38 
Thanks for responding so quickly. After messing about, I was able to figure out how to get it to load the questions from the existing DB. Thanks for writing it. It really helped me out in this instance. Much appreciated. Cheers, Jamie
GeneralRe: Exam Questions in a SQLDB Pin
Member 963246926-Nov-12 11:19
memberMember 963246926-Nov-12 11:19 
GeneralMy vote of 2 Pin
surendramarri12-Jan-11 0:57
membersurendramarri12-Jan-11 0:57 
GeneralMy vote of 4 Pin
HardikKSavaliya6-Dec-10 3:42
memberHardikKSavaliya6-Dec-10 3:42 
GeneralMy vote of 3 Pin
saxenaabhi613-Sep-10 19:21
membersaxenaabhi613-Sep-10 19:21 
GeneralRe: My vote of 3 Pin
vallarasus1-Jun-11 8:55
membervallarasus1-Jun-11 8:55 
GeneralMy vote of 1 Pin
j03x213-Sep-10 7:31
memberj03x213-Sep-10 7:31 
GeneralMy vote of 2 Pin
Sandeep Mewara28-Aug-10 5:41
mentorSandeep Mewara28-Aug-10 5:41 

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