Progress Bar in C# Winforms App

Question

I have no trouble getting a progress bar to work in a sample c# winforms app when using a BackgroundWorker and doing something like this:

private void Form1_Load(object sender, EventArgs e)

        {

            // Start the BackgroundWorker

            // Creates thread and DoWork method begins.

            backgroundWorker1.RunWorkerAsync();

        }

        private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)

        {

            for (int i = 1; i <= 100; i++)

            { 

                // Wait 100 ms at each iteration in order to see the progress

                Thread.Sleep(100);

                // Report Progresss

                backgroundWorker1.WorkerReportsProgress = true;

                backgroundWorker1.ReportProgress(i);

            }

        }

        private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e)

        {

            // Change the value of the ProgressBar to the BackgroundWorker progress.

            progressBar1.Value = e.ProgressPercentage;

            // Set the text of the titlebar

            this.Text = e.ProgressPercentage.ToString();

        }



but this just adds to the progress bar each time through the loop until reaching 100. In a real application though I want to start the progress bar when I select a file, then add progress to it until the entire process of retrieving data data from the file selected, build a sql query, executing the query and writing to a file completes. Since I'm not just adding to the bar each time through a loop I'm not sure how to go about doing this. Could anyone provide a real example? 


Thanks