Question

Web Developer here and need some advice on how to achieve what must be a common requirement in Windows Forms.

I have a windows client app that calls a business object in a separate project to perform some long running tasks. Difference to other examples is that the process live in another class library i.e. Business.LongRunningTask();

I have a list box in the client that I would like to have logged to by the task. I can run the process on the UI thread passsing in the instance of the textbox and calling Application.DoEvents() when I log to the textbox from within the task. All fine, but not elegant and would prefer not to call Application.DoEvents();

If I run the long running process on a separate thread using delegates I cannot access the textbox or delegates created in the windows client form which rules out BeginInvoke calls.

Surely this is bad design on my part and would appreciate some feedback.

Answer 1

You’re looking for the BackgroundWorker class.

To execute a time-consuming operation in the background, create a BackgroundWorker and listen for events that report the progress of your operation and signal when your operation is finished.

You can find a complete example here: http://msdn.microsoft.com/en-us/library/b2zk6580(v=VS.100).aspx#Y1351