SQL Query inside BackgroundWorker

Question

I am looking for implementation of background worker and progress bar. All I can find is a simulation using the Threading.Sleep(). Samples are all working but its not working if change the simulation to actual SQL query.

Where should I insert the query in below code, please help. .NET-2.0

void m_oWorker_DoWork(object sender, DoWorkEventArgs e)
    {
        // The sender is the BackgroundWorker object we need it to
        // report progress and check for cancellation.
        //NOTE : Never play with the UI thread here...
        for (int i = 0; i < 100; i++)
        {
            Thread.Sleep(100);

            // Periodically report progress to the main thread so that it can
            // update the UI.  In most cases you'll just need to send an
            // integer that will update a ProgressBar                    
            m_oWorker.ReportProgress(i);
            // Periodically check if a cancellation request is pending.
            // If the user clicks cancel the line
            // m_AsyncWorker.CancelAsync(); if ran above.  This
            // sets the CancellationPending to true.
            // You must check this flag in here and react to it.
            // We react to it by setting e.Cancel to true and leaving
            if (m_oWorker.CancellationPending)
            {
                // Set the e.Cancel flag so that the WorkerCompleted event
                // knows that the process was cancelled.
                e.Cancel = true;
                m_oWorker.ReportProgress(0);
                return;
            }
        }

        //Report 100% completion on operation completed
        m_oWorker.ReportProgress(100);
    }

Answer 1

By "the query", it sounds like you only have one operation to do. This makes a progress bar tricky, since there is no way of really measuring the progress of an SQL query. It can't tell you how much longer it is going to be. You might just want to use the non-committal infinite scrolling busy indicator while you perform the query.

Answer 2

You should execute any sql query, which is the real task of this background worker, just after checking for CancellationPending.