CODEWITHSUNDEEP
c#winforms
i'm stuck
i'm stuck

Reputation: 3

How do i display a progress bar while loading a datatable to DataGridview?

I have a method called GetAllRecords() that will return a datatable of 200K records. When I checked it took about 5 seconds to load data to the datagrid and window froze. 

DataTable dt = Records.GetAllRecords();

I know I have to use Background worker controls and it's three events, but I cannot figureout how to use them properly. For instance, the progress bar must show real progress not a fake one. I could slow the progress bar using sleep() of the thread class but it would be a fake progress bar.

  1. Could any one here please give me step by step instructions on how to create a real progress bar on my windows form?

  2. Before .NET 2.0 there was not Background worker control, in those days how programmer wrote real progress bars?

thanks

Upvotes: 0

Views: 9395

Answers (2)

sara
sara

Reputation: 3589

For the basics on how to implement a BackgroundWorker and a ProgressBar you can consult the examples given in the MSDN pages for ProgressBar and BackgroundWorker

As for actually making the percentage completed-property of your ProgressBar make sense, the key lies in finding a meaningful value to use as the argument for BackgroundWorker.ReportProgress(int). As you have probably noticed, in most tutorials and examples, people will normally just do a Thread.Sleep(100) inside a for-loop from 1 -> 100 and then send the iteration variable as the argument to ReportProgress.

The easiest solution for you is probably to set the ProgressBarStyle property to Marquee. That way your users can rest assured that your application hasn't frozen and that progress IS being made, although they won't know how long it will take for the operation to complete.

Upvotes: 0

Matt
Matt

Reputation: 2682

If you do a search of the site, as well as Google, you'll see that there are several attempts at doing this:

SO Link

MSDN Link

These solutions basically update the progress bar after you add each row to the grid, though if you're trying to show progress for an actual database call I don't think you'll be able to be very accurate on that.

I think the main problem you'll have is that you won't have event hooks to let you know exactly where the time-consuming part of the binding comes into play. I'm assuming that it takes 5 seconds once you bind the data to the grid and that you're not counting the load time of actually pulling down the records.

Pre-BackgroundWorker

The BackgroundWorker class is basically just a convenience to you handling the threading yourself and invoking any progress back to the UI thread for you. You would have to spawn your own thread, and call BeginInvoke on your control once work is done to apply the data to the UI thread, since you can't make changes to the UI on any thread but the main one.

Upvotes: 2

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