How can I listen to an event in the main thread created by another thread?

Question

2.00/5 (1 vote)

See more:

On the UI I’m creating a thread:
ConetarBiometriaThread = new Thread(new ThreadStart(ConectarBiometria));
ConetarBiometriaThread.IsBackground = true;
ConetarBiometriaThread.Start();

…
private void ConectarBiometria()
{
axCZKEM1 = new zkemkeeper.CZKEMClass();
try
{
bIsConnected = axCZKEM1.Connect_Net("192.168.1.201", 4370);
axCZKEM1.OnVerify += new zkemkeeper._IZKEMEvents_OnVerifyEventHandler(axCZKEM1_OnVerify);
axCZKEM1.StartIdentify();
}
catch
{ }
}

Now I need to be able to listen to axCZKEM1_OnVerify on the main thread…but I have no idea how….

Posted 19-Oct-14 5:12am

marco.constantino

Add a Solution

Comments

Sergey Alexandrovich Kryukov 19-Oct-14 13:33pm

If you create some thread by another thread, in what sense can it be called "main thread". The problem is very simple:

Event is invoked in an instance of some class/struct. Invocation takes place in some thread. It does not matter how you "listen" — you just add a handler in the invocation list of some event instance. The thread is determined by the thread performing invocation, so your handler will be called in that thread.

Now, you can think in terms of consequence of this fact. If this is not clear, please explain your goal and your problem, then I'll answer.

In particular, what is your thread to handle the event: UI or not? What should it do? If UI, what kind of UI (WPF, forms, anything else?)?

—SA

BillWoodruff 19-Oct-14 15:42pm

I think this CodeProject example might help you:

http://www.codeproject.com/Articles/1280/Worker-Threads-in-C

Sergey Alexandrovich Kryukov 20-Oct-14 0:53am

Despite of high popularity, I think it's a pretty bad article. A thread stopping procedure along, with Application.DoEvents tells the tale. I would not advice anyone to follow this article.
—SA

Ziee-M 20-Oct-14 11:23am

I totaly agree, i used Application.DoEvents in long running process and it ends by a crash : unhandled exception.

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Sidtrey · Answer 1 · 2014-10-23T04:51:00

Solution 1

Why not just listen to a static event from ConectarBiometria?

Posted 23-Oct-14 4:51am

Sidtrey