VB.Net - Cancel Long Running Process or Selection User Didn't Want

Thank you for your reply.   Since my project is in production already, how do I find out what the User clicked on so I can put it in the  DoWork method of that BGW? Or is this not possible?

Thanks for your help,
jimbo99999

Better yet, if you are using .NET 4 or higher, you can use task's with a CancellationToken

Microsofts Examples -

Single Task Cancellation - https://msdn.microsoft.com/en-us/library/dd997396(v=vs.110).aspx
Task and Children Cancellation - https://msdn.microsoft.com/en-us/library/dd537607(v=vs.110).aspx

-saige-

Thanks for responding.  Unfortunately I am not at 4 or higher.

how do I find out what the User clicked on so I can put it in the  DoWork method of that BGW? Or is this not possible?

It's possible, but it's not really possible for us to determine. You'd have to first define the process you want to move to that background worker, then define when/where the user could cancel.

For example, I have a DataGridView that takes quite a while to fill (it pulls a lot of data, and perform quite a few processes on each line). I moved my "LoadData" event to the BackgroundWorker, and now when the user loads data, they can continue using the machine while the DGV is loaded in the background. If they want to cancel, I included a Cancel button, and use code like I showed earlier to cancel the process.

Hello Scott

Thank you for your reply.  That is very similar to my issue. The bulk of the problems stem from when I am exporting from the DataGridView. I have processes that retrieve additional detail data for the records in the grid.  That combined with record volume in the grid causes me headaches.  I will try one of my grid exports to excel in the background.  This is my first time using this setup.  

Thanks again,
jimbo99999

I have much the same with an export from one of my datagrids. My DGVs are based on Datatables, so when I need to export I declare the datatable at Form level and then call my background worker to perform the export. The BGW uses that form-level DataTable to export, and I report back to the user when it's finished.

Hello There Scott

I am trying to call the button click that is long running for the User.  I am getting that cross-thread operation not valid message.  I am trying to figure out the ProcessChanged you mentioned.  If I back up a bit here...Is it even possible to call the button click as the process?
If it is not possible, can I "convert" the existing code behind the button to run in the background?

Thanks,
jimbo99999

BackgroundWorker.CancelAsync stops async thread execution but it doesn't stop 'heavy' SQL command. Use SQLCommand.Cancel method to cancel SQLCommand execution.

Is it even possible to call the button click as the process

I'm not sure, but I'd think you could not. If you have code that needs to be run from the background worker, then move that code to a function or sub, and call that function/sub.

cross-thread operation not valid

That often means you're trying to work with UI components (like a Textbox, perhaps) in the background worker. For example, you could not change the value of a Form's Label in the RunWork function.

I adjusted a couple things to not work with the UI and avoid the error.  It is working great.  The User is able to move the form and minimize it with no issues.  2 out of 3 things are done. I just have to figure out the cancel part. Poking around it looks like the Cancel is a little more tedious as I have not come to a solution yet for it.

Author seems to have adopted the suggestion solution, and I can verify that it works to move processing away from the UI thread, making the machine responsive during the long running operation