Multi-Threading: Accessing Main Thread Objects

[Mythran]

I've read some documentation about accessing objects created in other
threads and the code below is similar to what I've gathered for what I have
to do:

private delegate void SetCursorCallBack(Cursor cursor);

// - Checks to see if the current thread is the creator of the current Form.
If the form was
// created on another thread, call Invoke so the delegate is ran in the
creating thread.
private void SetCursor(Cursor cursor)
{
if (this.InvokeRequired()) {
SetCursorCallBack callBack = new SetCursorCallBack(SetCursor);
Invoke(callBack, cursor);
} else {
this.Cursor = cursor;
}
}

// This event gets fired in the secondary thread (not the thread that
created the form).
private void SomeVarName_SomeEventFiredFromAnotherThread(
object sender,
EventArgs e
)
{
SetCursor(Cursors.Default);
}

The comments in the code above are for YOUR consumption, this isn't exactly
what I have as I have snipped quite a bit of the custom code that is
irrelevant.

Is there a less-involved way to accomplish setting the properties of an
object created in a thread other than the current thread? If not, I can do
this fine, and I understand it, just wondering

Thanks,
Mythran

 

[Marc Gravell]

// here could be any thread
this.Invoke((MethodInvoker) delegate
{ // this bit runs on the UI thread
this.Cursor = Cursors.Default;
});

Marc

 

[Linda Liu[MSFT]]

Thanks Marc and Pete for your excellent replies!

Hi Mythran,

Your code to handle the cross-thread operation is correct. But if you want
a convenient way to do that, as Marc and Pete have suggested, you can use
anonymous method and MethodInvoker to do it.

For example:

private void SetCursor(Cursor cursor)
{
this.Invoke((MethodInvoker)delegate { this.Cursor = cursor; });

}

Hope this helps.
If you have any question, please feel free to let me know.

Sincerely,
Linda Liu
Microsoft Online Community Support

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[Mythran]

[...]
Is there a less-involved way to accomplish setting the properties of an
object created in a thread other than the current thread? If not, I can
do this fine, and I understand it, just wondering

Please see:
http://groups.google.com/group/micr...csharp/browse_thread/thread/c326c7700d2cf8a1/

We just had this discussion.

Pete

wow, your right, exactly what I asked...google must not have indexed that
yet, I didn’t get a hit off it before I posted...or maybe I just missed
it...anywho, thanks.

Mythran

 

[Benjamin Vigneaux]

Ok, perhaps i'm going a little bit of topic with my next question... but I
didn't find a appropiate group to post this question and since everyone here
knows a bit of everything perhaps I could get an answer.

Basically what I need if to build a homeserver, well.. at least, set it up,
cause I have 3 computers that I could clusterize ,even though a friend told
me that clusterizing migh not be the best idea form what i have in mind,
which is hosting a website/blog and file server, and the idea is that these
3 computers share one single harddrive.

Which SO would be appropiate to do this (ok, it's pretty obvious that
windows server would be an obvious suggestion, but i can't afford it right
now) perhaps a linux distro? is clusterizing a good idea for this? or
perhaps set it up as some kind of distributed database?