Blinking Label and its timer logic

Question

Hello , below is the code which i used to make the label appear like flashing electric LED display . I have managed to make the label appear like flashing but The problem

1. after the first round of displaying ends , I want that the full text of label should not flash and the whole text of label ,change its color to lime for 1 second , then it should again its color to red for 1 second . and after the blinking should continue .

  public partial class animated_welcome_screen : Form
    {
        int counter = 0;
        int mimic = 0;
        string text;
        public animated_welcome_screen()
        {
            InitializeComponent();
        }

        private void animated_welcome_screen_Load(object sender, EventArgs e)
        {
            text = label1.Text;
            mimic = text.Length;
            label1.Text = "";
        }

        private void timer1_Tick(object sender, EventArgs e)
        {
            counter++;
            if(counter >  mimic)
            {
                counter = 0;
               // label1.ForeColor = Color.Lime;
              //  timer1.Stop();
               // counter++;
              //  if(counter==1)
              //  {
              //      label1.ForeColor = Color.Red;
              //  }
                label1.Text = "";
              //  timer1.Start();
               // counter = 0;
            }
            else
            {
                label1.Text = text.Substring(0, counter);
                if (label1.ForeColor == Color.Lime)
                {
                    label1.ForeColor = Color.Red;                  
                }
                else
                {
                    label1.ForeColor = Color.Lime;
                }
            }
        }
    }

the timer is enabled to true and interval is 100 . the label text is Please Wait....

Answer 1

Hi @Shaifali jain , Welcome to Microsoft Q&A,

I don't recommend using goto: statements, it makes the code difficult to maintain and understand.

using System;
using System.Drawing;
using System.Windows.Forms;

namespace WindowsFormsApp1
{
    public partial class Form1 : Form
    {
        private int counter = 0;
        private int mimic = 0;
        private string text;
        private int state = 0;
        private const int MaxCounterValue = 20; // Can be adjusted as needed
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            text = label1.Text;
            mimic = text.Length;
            label1.Text = " Please Wait...";
            state = 0;
            timer1.Start();
        }

        private void timer1_Tick(object sender, EventArgs e)
        {
            counter++;

            switch (state)
            {
                case 0:
                    if (counter > mimic)
                    {
                        state = 1;
                        counter = 0;
                        label1.ForeColor = Color.Lime;
                    }
                    else
                    {
                        label1.Text = text.Substring(0, counter);
                        label1.ForeColor = (label1.ForeColor == Color.Lime) ? Color.Red : Color.Lime;
                    }
                    break;

                case 1:
                    if (counter > MaxCounterValue)
                    {
                        state = 2;
                        counter = 0;
                        label1.ForeColor = Color.Red;
                    }
                    break;

                case 2:
                    if (counter > MaxCounterValue)
                    {
                        state = 0;
                        counter = 0;
                    }
                    break;
            }
        }
    }
}

In addition to using timer controls, you can also use await to achieve similar animation effects. You can use async and await to manage asynchronous operations.

Because using the timer control will trigger events on the Ui thread regularly, it may block the main thread. Asynchronous operations using await will not block the UI thread.

And you don't need to calculate the time manually.

Code show as below:

using System;
using System.Drawing;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace _9_19_x
{
    public partial class Form1 : Form
    {
        private string text;
        private int state = 0;
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            text = label1.Text;
            label1.Text = "Please Wait...";

            Task task = AnimateTextAsync();
            //MessageBox.Show("Task started."); Execute immediately
            //await AnimateTextAsync(); needs to change Form1_Load to async
            //MessageBox.Show("Task started."); will not be executed immediately
        }
        private async Task AnimateTextAsync()
        {
            while (true)
            {
                switch (state)
                {
                    case 0:
                        for (int i = 1; i <= text.Length; i++)
                        {
                            label1.Text = text.Substring(0, i);
                            label1.ForeColor = Color.Lime;
                            await Task.Delay(100); // wait 1 second
                        }
                        state = 1;
                        break;

                    case 1:
                        await Task.Delay(1000); // wait 1 second
                        label1.ForeColor = Color.Red;
                        await Task.Delay(1000); // wait 1 second
                        state = 2;
                        break;

                    case 2:
                        await Task.Delay(1000); // wait 1 second
                        state = 0;
                        label1.Text = "Please Wait...";
                        break;
                }
            }
        }
    }
}

Best Regards,

Jiale

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Answer 2

A simpler method is to disable the timer and do initial processing in an asynchronous Shown event.

private void animated_welcome_screen_Load(object sender, EventArgs e) {
    timer1.Stop();
    text = label1.Text;
    mimic = text.Length;
    //label1.Text = "";
}

private async void animated_welcome_screen_Shown(object sender, EventArgs e) {
    label1.ForeColor = Color.Lime;
    await Task.Delay(1000);
    label1.ForeColor = Color.Red;
    await Task.Delay(900);
    timer1.Start();
}