How to implement a blinking label on a form

Question

I have a form that displays queue of messages and number this messages can be changed. Really I want to blink label (queue length) when the number of messages were increased to improve form usability. Should I implement custom control and use additional thread or timer to change color of label? Has anybody implemented so functionality? What is the best solution (less resources and less performance degradation) to implement so behaviour?

SOLUTION:

Form's component with timer that can restrict number of animations per second and implement fade out effect to external control background color.

@David: blinking is better than the marquee nonsense, at least. I have coworkers who are desperately trying to re-introduce the marquee to iPhone/iPad apps - they were not alive in the 90's, as far as I can tell. — MusiGenesis, Feb 18 '11 at 14:42
@David Heffernan how can form attract user attention? Or maybe it's useless feature? — garik, Feb 18 '11 at 22:01
Blinking text was pivotal in the success of a prank I pulled on a co-worker. The impact would have been significantly reduced if I didn't have access to this technology. — Jason, Mar 14 '13 at 07:14

score 30 · Answer 1 · edited Aug 09 '16 at 22:07

30

The following is blinking using async and await

private async void Blink(){
    while (true){
        await Task.Delay(500);
        label1.BackColor = label1.BackColor == Color.Red ? Color.Green : Color.Red;
    }
}

edited Aug 09 '16 at 22:07

iliketocode

6,978
5
46
60

answered Mar 18 '15 at 08:46

IdontCareAboutReputationPoints

1,404
20
25

1

What's your approach killing this process? – Baz Guvenkaya Oct 25 '16 at 03:26
you can add a check for a bool var inside the loop `_continueBlink` and check while it's true continue, else leave the loop, you can then set it to `false` somewhere else to leave blinking loop – IdontCareAboutReputationPoints Oct 25 '16 at 09:32

score 24 · Answer 2 · edited Jul 11 '18 at 13:15

24

I know this is a really old post, but anyone looking for something a little more versatile than the Boolean solutions posted may get some use out of the following:

using System.Diagnostics;
using System.Threading.Tasks;

private async void SoftBlink(Control ctrl, Color c1, Color c2, short CycleTime_ms, bool BkClr)
{
    var sw = new Stopwatch(); sw.Start();
    short halfCycle = (short)Math.Round(CycleTime_ms * 0.5);
    while (true)
    {
        await Task.Delay(1);
        var n = sw.ElapsedMilliseconds % CycleTime_ms;
        var per = (double)Math.Abs(n - halfCycle) / halfCycle;
        var red = (short)Math.Round((c2.R - c1.R) * per) + c1.R;
        var grn = (short)Math.Round((c2.G - c1.G) * per) + c1.G;
        var blw = (short)Math.Round((c2.B - c1.B) * per) + c1.B;
        var clr = Color.FromArgb(red, grn, blw);
        if (BkClr) ctrl.BackColor = clr; else ctrl.ForeColor = clr;
    }
}

Which you can call like such:

SoftBlink(lblWarning, Color.FromArgb(30, 30, 30), Color.Red,2000,false);
SoftBlink(lblSoftBlink, Color.FromArgb(30, 30, 30), Color.Green, 2000,true);

edited Jul 11 '18 at 13:15

Deniz

420
1
4
18

answered Jun 09 '17 at 22:09

Jim Simson

2,656
3
20
29

This has been my preferred solution. – Harold_Finch Jul 21 '17 at 10:21
Could you provide this example for NET 1.1? I would like to put it in a legacy project. Also is this working for any foreground and backgound color? – Rodri Nov 15 '17 at 21:28
I use NET 3.5, and instead of async/await this solution https://stackoverflow.com/a/42587193/3118667 but it's not working very well – prototype0815 Feb 20 '18 at 08:29
No I got it ! It works with WaitNMilliseconds(), not WaitNSeconds(). – prototype0815 Feb 20 '18 at 09:03

score 14 · Answer 3 · answered Feb 18 '11 at 15:04

Timer timer = new Timer();
timer.Interval = 500;
timer.Enabled = false;

timer.Start();

if( messagesNum > oldMessagesNum)
  timer.Tick += new EventHandler( timer_Tick );
else
  timer.Tick -= timer_Tick;

void timer_Tick( object sender, EventArgs e )
{
   if(messageLabel.BackColor == Color.Black)
      messageLabel.BackColor = Color.Red;
   else
      messageLabel.BackColor = Color.Black;
}

Here is a pretty simple implementation that would work inside your form. You could also create a custom control with the same code and just throw the Timer.Start() into a method for that control.

score 4 · Answer 4 · answered Feb 18 '11 at 14:40

Create your own UserControl for this, one that inherits from Label instead of from Control directly. Add a StartBlinking method, in which you start a Timer object whose tick event alters the style of the label (changing the BackgroundColor and ForegroundColor properties each time to create the blink effect).

You could also add a StopBlinking method to turn it off, or you could have your Timer stop itself after 5 seconds, perhaps.

score 3 · Accepted Answer · edited Jun 26 '20 at 15:06

3

You can create a custom component and events to start blinking --which I think is a good solution. The Blinking you can implement with a timer.

edited Jun 26 '20 at 15:06

Jim Simson

2,656
3
20
29

answered Feb 18 '11 at 14:35

Sergey Vedernikov

7,433
2
24
27

score 2 · Answer 6 · edited Aug 09 '16 at 22:07

2

Can you use an animated .gif instead (perhaps as the background of the number)? it would make it look like old school web pages, but it might work.

edited Aug 09 '16 at 22:07

iliketocode

6,978
5
46
60

answered Feb 18 '11 at 14:38

vlad

4,670
1
30
36

1

-1 because downvotes are a good way to learn to avoid grisly hacks. :) – MusiGenesis Feb 18 '11 at 14:44
1

@MusiGenesis that's personal opinion :P – vlad Feb 18 '11 at 14:53
Share by multiple people, hacks are hacks, and should only be used as a last resort. – Security Hound Feb 18 '11 at 16:15
3

@Ramhoud I'm guessing you didn't understand what I said. I was arguing that my solution was not a hack. It correctly solves the problem of "bringing attention to this part of the screen". – vlad Feb 18 '11 at 16:27

score 0 · Answer 7 · answered Aug 20 '18 at 11:59

You can use Timer class here. Here what I have implemented. Label color blinking on Button_click Event.

//click event on the button to change the color of the label
public void buttonColor_Click(object sender, EventArgs e)
        {
            Timer timer = new Timer();
            timer.Interval = 500;// Timer with 500 milliseconds
            timer.Enabled = false;

            timer.Start();

            timer.Tick += new EventHandler(timer_Tick);
        }

       void timer_Tick(object sender, EventArgs e)
    {
        //label text changes from 'Not Connected' to 'Verifying'
        if (labelFirst.BackColor == Color.Red)
        {
            labelFirst.BackColor = Color.Green;
            labelFirst.Text = "Verifying";
        }

        //label text changes from 'Verifying' to 'Connected'
        else if (labelFirst.BackColor == Color.Green)
        {
            labelFirst.BackColor = Color.Green;
            labelFirst.Text = "Connected";
        }

        //initial Condition (will execute)
        else
        {
            labelFirst.BackColor = Color.Red;
            labelFirst.Text = "Not Connected";
        }
    }

How to implement a blinking label on a form

7 Answers7

Linked

Related