If you need the background operation to report on its progress, you can call the BackgroundWorker.ReportProgress(int) method to raise the BackgroundWorker.ProgressChanged event. The BackgroundWorker.WorkerReportsProgress property value must be true, or BackgroundWorker.ReportProgress(int) will throw an InvalidOperationException.

It is up to you to implement a meaningful way of measuring your background operation's progress as a percentage of the total task completed.

The call to the BackgroundWorker.ReportProgress(int) method is asynchronous and returns immediately. The BackgroundWorker.ProgressChanged event handler executes on the thread that created the System.ComponentModel.BackgroundWorker.

Namespace: System.ComponentModel
Assembly: System (in System.dll)
Assembly Versions: 2.0.0.0, 4.0.0.0
Since: .NET 2.0