What is the best way to wait for a certain time (say 10 seconds) in C#?

Question

I want to wait for 15 seconds, then the control should resume from the next statement.

I don't have anything else to do while waiting (Just waiting).

I know that there is Thread.Sleep(15000) . What I don't know is the best method to wait? What are the limitations of this?

The code would be like this:

Method()
{
   statement 1;
   statement 2;
   //WaitFor 15 secs here;
   statement 3;
}

Answer 1

The disadvantage of Thread.Sleep is if this is called in your GUI thread (the thread that processes GUI events, for example, a button click handler method, or a method called from a button click handler, etc.) then you application will appear to freeze and be nonresponsive for those 15 seconds.

It would be perfectly fine if you had explicetly created a seperate thread and called Thread.Sleep in it, assuming you don't mind that thread not doing anything for 15 seconds.

The alternative would be to create a Timer and start it after stmt 2, and place stmt 3 in the Tick event handler for the timer, and also stop the timer in that handler.

Answer 2

This may not be a direct answer to your question. I would say check whether your process flow is better than checking whether the code is better ;-)

Are you waiting for 15 seconds just to make sure stmt2; is complete? If so then adding an handler, as soon as stmnt 2 is executed, would be a better solution (?)

You can also use a timer to wait. Thread.sleep is a bad design. We have a similar question which talks about the comparison using Thread.sleep and Timer .

Answer 3

Thread.sleep seems a sensible thing to do if there isn't anything else to do while waiting. It puts the thread to sleep for that time so it doesn't use any CPU resources.

Answer 4

Try something like the following:

void Method()
{
    console.log('statement 1');
    console.log('statement 2');

    var timer = new System.Threading.Timer(
        o =>   // timer callback
        {
           console.log('statement 2');
        },
        15000, // Delay
        0      // Repeat-interval; 0 for no repeat
    );
}

Syntax is C# 3.0, uses a lambda expression to effectively create a closure around statement #3. With this, you could use any local variables of Method. A thing to note, however, is that with this method, or any other timer-based method...the function will return immediately after creating the timer. The function won't block until the Timer executes. To achieve that, the only thing I can think of is to actually use threads and make Method() block on a signal (ie WaitHandle, ResetEvent, etc.) until the timed call on the other thread completes.

Answer 5

You could always use a timer and then execute code after the set duration. However, if you don't actually have to do anything and just want to wait at a particular point in code, then I think Thread.Sleep(150000); is sufficient. [Edit: spelling]

Answer 6

If you always want to wait for a given time, then Sleep is useful. Obviously you shouldn't do this on a thread where timely responses are expected.

Keep in mind that your thread will sleep for the duration in all cases. If for some reason you want the thread to resume sooner, you're better off using signaling or callbacks. By using either of these instead of Sleep , you will minimize the needless wait time.

Answer 7

void Method()
{
    Statement1();
    Statement2();

    // Start the timer for a single 15 second shot.
    // Keep a reference to it (Mytimer) so that the timer doesn't get collected as garbage
    Mytimer = new System.Threading.Timer((a) =>
        {
            // Invoke the 3rd statement on the GUI thread
            BeginInvoke(new Action(()=>{ Statement3(); }));
        }, 
    null,
    15000, // 15 seconds
    System.Threading.Timeout.Infinite); // No repeat
}

Answer 8

I don't sure 100%, but if you really need your method to return after waiting 15 sec, try following:

Method()
{
   stmt1();
   stmt2();

   int time = DateTime.Now.Millisecond;
   while (15*1000 > DateTime.Now.Millisecond - time)
   {
       Thread.Sleep(10)
       Application.DoEvents();
   }
   stmt3();
}