The BackgroundWorker is really good for this. In fact, it was - at least partially - designed for it! :)

public partial class Form1 : Form
{
    private BackgroundWorker worker;

    public Form1()
    {
        InitializeComponent();
        progressBar1.Minimum = 0;
        progressBar1.Maximum = 100;
    }

    private void Form1_Load(object sender, EventArgs e)
    {
        worker = new BackgroundWorker();
        worker.DoWork += new DoWorkEventHandler(worker_DoWork);
        worker.ProgressChanged += new ProgressChangedEventHandler(worker_ProgressChanged);
        worker.WorkerReportsProgress = true;
        progressBar1.Value = progressBar1.Minimum;
        worker.RunWorkerAsync();
    }

    void worker_ProgressChanged(object sender, ProgressChangedEventArgs e)
    {
        progressBar1.Value = e.ProgressPercentage;
        label1.Text = e.ProgressPercentage + "%";
    }

    void worker_DoWork(object sender, DoWorkEventArgs e)
    {
        for (int i = 1000; i >= 0; i--)
        {
            Thread.Sleep(50);
            int percent = (1000 - i) / 10;
            worker.ReportProgress(percent);
        }
    }
}

you can find ur answer in this thread by making a thread or a background worker:
http://www.debugging.com/bug/23453

considering changing the progress bar color, you have to use the user32.dll code to change the color of a window control or can change the forecolor while enablingvisualstyle. You can find it in this page:

http://stackoverflow.com/questions/778678/how-to-change-the-color-of-progressbar-in-c-net-3-5

On the color changing point, according to the documentation you can't change the foreground and background colors in XP and above if you've enabled visual styles. However, these are enabled by default when you create a windows forms application in VS.

If you examine the Main() method in your program.cs file, you'll need to remove this line to disable them:

Application.EnableVisualStyles();

That is a wonderful code from Foamy. Thank You very much.

I want the percentage to be inside the Progress Bar, so I have this: But the percentage disappears after it reaches 100%. How do I enable the percentage to be visible even after it reaches 100%? thanks.

void worker_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
progressBar1.Value = e.ProgressPercentage;

int percent = (int)(((double)progressBar1.Value / (double)progressBar1.Maximum) * 100);
progressBar1.CreateGraphics().DrawString(percent.ToString() + "%", new Font("Arial", (float)8.25, FontStyle.Regular), Brushes.Black, new PointF(progressBar1.Width / 2 - 10, progressBar1.Height / 2 - 7));

// label1.Text = e.ProgressPercentage + "%";
}

As I didn't knew how to bring that % count embidded into the progressBar1 so I had customised it with a solution from my fresher's head:

progressBar1 > Right Click > send to back,
label1 > Right Click > bring to front,
Dragged label1 in middle of progessBar1

then I added the code

if (percent==100)
{
label1.Text = "Loading Complete";
}

// in label1's property I would put label1's text as ="";

// Then in worker_ProgressChanged I will put
if (percent==100)
{
label1.Text=e.ProgressPercentage+"%";
or
label1.Text = "100%";
}

I think the problem is that you're not erasing the previous percentage before drawing the new one and consequently you're getting a jumble of the two.

Whilst gsvirdi's suggestion works, the bar is obscured by the label.

Try this instead:

// add this private field
private int lastPercentage = 0;

void worker_ProgressChanged(object sender, ProgressChangedEventArgs e)
{            
    if (e.ProgressPercentage == lastPercentage) return; //EDIT added this line
    progressBar1.Value = e.ProgressPercentage;   
    Graphics g = progressBar1.CreateGraphics();            
    Font f = new Font("Arial", 8.25f, FontStyle.Regular);
    int w = progressBar1.Width / 2 - 10;
    int h = progressBar1.Height / 2 - 7;
    SolidBrush sb = new SolidBrush(progressBar1.BackColor); 
    g.DrawString(lastPercentage.ToString() + "%", f, sb, w, h);
    g.DrawString(e.ProgressPercentage.ToString() + "%", f, Brushes.Black, w, h);
    sb.Dispose();
    f.Dispose();
    g.Dispose();
    lastPercentage = e.ProgressPercentage;         
}

hi Vulpes,

my code below works, but the last 100% disappears. Yours 100% disappear too. I want the 100% to be visible.

void worker_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
progressBar1.Value = e.ProgressPercentage;

int percent = (int)(((double)progressBar1.Value / (double)progressBar1.Maximum) * 100);
progressBar1.CreateGraphics().DrawString(percent.ToString() + "%", new Font("Arial", (float)8.25, FontStyle.Regular), Brushes.Black, new PointF(progressBar1.Width / 2 - 10, progressBar1.Height / 2 - 7));

}

foamy's and gsvirdi's code works fine with the Label, able to display the final 100%, but the bar is obscured by the label, which I do not want. I want the percentage to be inside the progress bar, without using the label.

your code and my code is not able to display the final 100%, persistently on the progress bar.

Will it be acceptable for u to keep the label1 on right side (end) of the progressBar1? This way till 99% the percentage is shown inside the progress bar, but on 100% the label1 on the end of the progress bar will show the progress percentage. I'm sorry as I won't be able to help with the code, I still have a long path to become expert in codeing :)

if it is some complex functions that takes some time to complete, and I want to trace its progress in percentage, how do I do that? I notice that the count down loop is easy to trace its percentage, because it has a variable counter. but say those complex functions call some other functions, how do I trace its progress till completion?

thanks.

It depends on the circumstances.

Sometimes there's no practicable way to measure progress towards completion, using a simple mathematical formula.

In such cases, you need to estimate in advance how long the operation will take and then change the ProgressBar in accordance with the percentage time elapsed since inception. You also need to avoid moving the progress bar up to 100% until the overall task has completed.

To give a smoother result, you might also want to set intermediate 'wait points' which are not to be exceeded until a particular sub-task has been completed and then to recalculate the estimated time to completion at those points.