Hi Chris
I apologize if this answer appears twice, but I got an error trying to post
the previous answer, so here goes.
When you do heavy processing inside the GUI thread (main thread in a windows
application) you won't have any processing time to perform GUI stuff. This
will cause a gray and/or non responsive interface.
You should move any heavy processing to a separate thread. The easiest way
to do this is by using a BackgroundWorker object like Gilles points out.
Below is an example of how this can be done using a background worker that
reports progress as well as supports aborting. Add a progressbar control as
well as two buttons with their Click event attached to button1_Click and
button2_Click
private BackgroundWorker worker;
public Form2()
{
InitializeComponent();
worker = new BackgroundWorker();
// Needed to fire the progresschanged event
worker.WorkerReportsProgress = true;
// Needed to be able to stop the processing
worker.WorkerSupportsCancellation = true;
// Any heavy processing should spawn from this event
worker.DoWork += new DoWorkEventHandler(worker_DoWork);
// This event fires when you want it to
worker.ProgressChanged += new
ProgressChangedEventHandler(worker_ProgressChanged);
// This event fires when the worker is done processing
worker.RunWorkerCompleted += new
RunWorkerCompletedEventHandler(worker_RunWorkerCompleted);
}
private void button1_Click_1(object sender, EventArgs e)
{
// Resett progressbar
progressBar1.Value = 0;
// Notify the worker object to start working
worker.RunWorkerAsync(@"C:\temp");
// You can put anything as an argument to this method
}
private void button2_Click(object sender, EventArgs e)
{
// Stop working
if (worker.IsBusy)
worker.CancelAsync();
}
void worker_DoWork(object sender, DoWorkEventArgs e)
{
DateTime start = DateTime.Now;
// This method is called when you use RunWorkerAsync
string path = e.Argument.ToString();
// e.Argument can be anything, including a complex object
for (int i = 0; i < 100; i++)
{
// Did someone cancel the work?
if (worker.CancellationPending)
{
// if so, then simply return
return;
}
// Simulate processing of a single file
// which in this case would take 1 seconds
// to process.
System.Threading.Thread.Sleep(1000);
// Report the number of files processed
worker.ReportProgress(i + 1);
// The parameter says intPercentage,
// but it can be any number you like
}
// the Result property can be used to provide information
e.Result = "100 files processed in " + (DateTime.Now -
start).TotalSeconds + " minutes";
}
void worker_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
// If the worker calls ReportProgress this method will be called.
progressBar1.Value = e.ProgressPercentage;
}
void worker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
// This method will be called when the worker is done processing or
cancelled
if (e.Result == null)
MessageBox.Show("Processing aborted");
else
MessageBox.Show(e.Result.ToString());
}
