Go Premium for a chance to win a PS4. Enter to Win

x
?
Solved

Wake me up in 500ms

Posted on 2006-07-09
6
Medium Priority
?
253 Views
Last Modified: 2010-04-16
Hi,
I have a requirement that when a button is clicked, I should wait 500ms and than open a message box.
However, when i use the Thread.Sleep(500) method, the GUI get freezed.

So what I need is some sort of mechanism that I supply a callback function to be called after a certain amount of milliseconds.

I know I can use timers, but I don't want to add a timer to my class and activate it, just for that delay.

So is there a function like this: InvokeAfterDelay(Delegate callback, int milliseconds) ?
0
Comment
Question by:PHILIPS_MED
  • 4
6 Comments
 
LVL 11

Accepted Solution

by:
vo1d earned 1200 total points
ID: 17067980
if you use the sleep method, the app running thread is paused.

if you dont want the control timer object, use the Thread.Timer object.
it is a timer object, which comes from the threadpool.
implement that timer object in your app, which interval is set to 500.
in the click eventhandler of your button, start the timer.
in the delegate of your timer, stop the timer first and show the messagebox.
this timer is a lightweight timer and needs nearly no resources.

0
 
LVL 11

Expert Comment

by:vo1d
ID: 17067994
sorry, the namespace for that timer object is:
System.Threading.Timer .
0
 

Author Comment

by:PHILIPS_MED
ID: 17068323
Hi vo1d,
If I understood you correctly, this is what I should put on the button.Click event handler:

new System.Threading.Timer(new TimerCallback(ShowMessageBox), null, 500, Timeout.Infinite);

And the timer will automatically stop and dispose itself?
0
Concerto Cloud for Software Providers & ISVs

Can Concerto Cloud Services help you focus on evolving your application offerings, while delivering the best cloud experience to your customers? From DevOps to revenue models and customer support, the answer is yes!

Learn how Concerto can help you.

 
LVL 86

Expert Comment

by:Mike Tomlinson
ID: 17068552
For longer delays, you can use code like below (VB.Net example):

    Private Sub Delay(ByVal DelayInSeconds As Integer)
        Dim ts As TimeSpan
        Dim targetTime As DateTime = DateTime.Now.AddSeconds(DelayInSeconds)
        Do
            ts = targetTime.Subtract(DateTime.Now)
            Application.DoEvents() ' keep app responsive
            System.Threading.Thread.Sleep(50) ' reduce CPU usage (keep value small to avoid lockups)
        Loop While ts.TotalSeconds > 0
    End Sub
0
 
LVL 11

Expert Comment

by:vo1d
ID: 17068578
correct.
0
 
LVL 11

Expert Comment

by:vo1d
ID: 17068583
your ShowMessageBox should look like this:
public void ShowMessageBox(Object stateInfo)
        {            
            MessageBox.Show("whatever");
        }
0

Featured Post

Technology Partners: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Introduction This article series is supposed to shed some light on the use of IDisposable and objects that inherit from it. In essence, a more apt title for this article would be: using (IDisposable) {}. I’m just not sure how many people would ge…
Summary: Persistence is the capability of an application to store the state of objects and recover it when necessary. This article compares the two common types of serialization in aspects of data access, readability, and runtime cost. A ready-to…
We’ve all felt that sense of false security before—locking down external access to a database or component and feeling like we’ve done all we need to do to secure company data. But that feeling is fleeting. Attacks these days can happen in many w…
Please read the paragraph below before following the instructions in the video — there are important caveats in the paragraph that I did not mention in the video. If your PaperPort 12 or PaperPort 14 is failing to start, or crashing, or hanging, …
Suggested Courses

963 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question