Question

I have a form in a vb.net windows form application called PolicyRefreshStatus.vb that has a ProgressBar control on it. From the main form called EditPolicy.vb I need to show PolicyRefreshStatus.vb over top of EditPolicy.vb – but the way things are wired I’m controlling the the ProgressBar and it’s steps from logic inside EditPolicy.vb.

If I display the PolicyRefreshStatus.vb bar using the .show() method things work fine. The problem is if the user clicks back on the main form then PolicyRefreshStatus.vb losses focus. If I show PolicyRefreshStatus.vb as a modal form using .ShowDialog() then execution halts in EditPolicy.vb after the .ShowDialog() statement.

so for example in the code:

 mPolicyRefreshStatus = New PolicyRefreshStatus
 mPolicyRefreshStatus.pbMax = mPolicy.ClaimsUpdateMax
 mPolicyRefreshStatus.ShowDialog()
 mPolicy.UpdateFromFIS() 

The line mPolicy.UpdateFromFIS() never executes because it’s waiting for the PolicyRefreshStatus form to close.

How can I show PolicyRefreshStatus in a modal form but let execution continue in EditPolicy.vb?

Answer 1

You’ve got a couple of related options.

This first is to pass the unit of work to the progress bar in the form of a delegate or a class implementing an Interface. Something like this (not checked for correctness, just a rough example):

mPolicyRefreshStatus = New PolicyRefreshStatus  
mPolicyRefreshStatus.pbMax = mPolicy.ClaimsUpdateMax  
mPolicyRefreshStatus.UnitOfWork = AddressOf(mPolicy.UpdateFromFIS())
mPolicyRefreshStatus.ShowDialog()  

Then within the progress form you can call back to the routine that actually does the work.

Another approach is to define events on your ProgressForm and then the owning/launching object can handle those events to do the work in. With this option you can create a fairly detailed set of events to be able to handle incremental work or cancels, but the concept is the same, youu are calling back from the progress form into launcher to perform the actual business logic.