StrataFrame Forum » StrataFrame Application Framework - V1 » Business Objects and Data Access (How do I?) » Delegate and Threading

Delegate and Threading

Scott Hershberger — Mon, 24 Sep 2007 20:57:07 GMT

I need to pass a delegate with a parameter to the thread manager, however, the threadmanager does not take a pure delegate and requires MicroFour.StrataFrame.Threading.ThreadManager.Delegate_ExecutionMethod which does not allow parameters. Is there anyway to get around this?

Public Delegate Sub GetData(ByVal passedInt As Integer)
Dim myMethod As MicroFour.StrataFrame.Threading.ThreadManager.Delegate_ExecutionMethod
myMethod = AddressOf GetDataSub

This obviously does not work since :

Method 'Public Sub GetDataSub(passedInt As Integer)' does not have the same signature as delegate 'Delegate Sub Delegate_ExecutionMethod()'

RE: Delegate and Threading

Trent L. Taylor — Mon, 24 Sep 2007 20:57:07 GMT

This is a topic that we cover in depth in the training class. There is a lot of detail that surrounds threading, events, and delegates. As for your question, you basically understand it. You would have to create a unique background worker thread for each threaded method that you wanted to call. Using the ThreadManager, you can fire off as many threads as you need through a single control while managing the events associated with the ThreadManager in a thread-safe manner.

RE: Delegate and Threading

Randy Jean — Mon, 24 Sep 2007 16:46:31 GMT

What are the pros/cons of using threadmanager vs. backgroundworker? Been reading up on the bgw control and seems to do a lot of what the threadmanager does but allows passing an object through RunAsync and also seems to allow updating user interface controls. The downside I see is that if I want multiple bgw I need to drop several of these on my form where with threadmanager I can just add another thread through AddProcess. New to this world of multi-threading so forgive my ignorance...

RE: Delegate and Threading

StrataFrame Team — Fri, 21 Sep 2007 13:28:14 GMT

I didn't realize that the ThreadManager had its own delegates... thought it used ThreadStart and ParameterizedThreadStart, but looks like it doesn't...

So, since you can't pass a parameter, looks like your best bet is going to be to store off that value within a shared variable somewhere and then access it from the other thread. Don't forget to use a SyncLock if you end up accessing that variable from more than one thread at the same time ;)

RE: Delegate and Threading

Scott Hershberger — Fri, 21 Sep 2007 11:19:40 GMT

Sorry...messed that code up a little ignore the delegate totally. It's just a normal sub with an integer param