invoke in events

[Ole]

Hi,

I have an instance of a class in which a thread is running. When a special
condition in that instance is met it raises an event to my main class (UI),
but I can't directly interact with the user interface controls in my
eventhandler without some sort of invoke. How should that be done - is it
possible to locate the invoke in the instance so that the eventhandler
actually belongs to the UI?

Thanks,
Ole

[Alberto Poblacion]

"Ole" <ol*@blabla.comwrote in message
news:er**************@TK2MSFTNGP02.phx.gbl...

I have an instance of a class in which a thread is running. When a special
condition in that instance is met it raises an event to my main class
(UI), but I can't directly interact with the user interface controls in my
eventhandler without some sort of invoke. How should that be done - is it
possible to locate the invoke in the instance so that the eventhandler
actually belongs to the UI?

The Invoke method should be invoked on a Control belonging to th UI. If
you pass to the instance of your class one such control (for instance the
"this" from the main form in your application), then it can use such control
to call Invoke and marshall execution into the main thread before raising
the event. Something similar to the following:

class MyClass
{
private Control ctl;
public Myclass(Control ctl)
{
this.ctl=ctl;
}

public event EventHandler theEvent;
private void EventRaiser()
{
if (theEvent!=null) theEvent(this, EventArgs.Empty);
}

void CodeThatRaisesEvent()
{
ctl.Invoke(new MethodInvoker(EventRaiser));
}
}

[Nicholas Paldino [.NET/C# MVP]]

Ole,

If you are concerned about not having to pass the instance of the form
to the class, what you could do is get the invocation list of the delegate
for the event you are firing. You would then cycle through the list, and
check the MethodInfo for the each delegate in the list. If the type it is
associated with implements ISynchronizeInvoke, then you can cast the target
of the delegate to that and invoke the event on through the Invoke
implementation (which is, in fact, what the Invoke method of Control is).

--
- Nicholas Paldino [.NET/C# MVP]
- mv*@spam.guard.caspershouse.com

"Ole" <ol*@blabla.comwrote in message
news:er**************@TK2MSFTNGP02.phx.gbl...

Hi,

I have an instance of a class in which a thread is running. When a special
condition in that instance is met it raises an event to my main class
(UI), but I can't directly interact with the user interface controls in my
eventhandler without some sort of invoke. How should that be done - is it
possible to locate the invoke in the instance so that the eventhandler
actually belongs to the UI?

Thanks,
Ole

[Ole]

Thanks for your help!
Ole

"Nicholas Paldino [.NET/C# MVP]" <mv*@spam.guard.caspershouse.comwrote in
message news:%2****************@TK2MSFTNGP02.phx.gbl...

Ole,

If you are concerned about not having to pass the instance of the form
to the class, what you could do is get the invocation list of the delegate
for the event you are firing. You would then cycle through the list, and
check the MethodInfo for the each delegate in the list. If the type it is
associated with implements ISynchronizeInvoke, then you can cast the
target of the delegate to that and invoke the event on through the Invoke
implementation (which is, in fact, what the Invoke method of Control is).

--
- Nicholas Paldino [.NET/C# MVP]
- mv*@spam.guard.caspershouse.com

"Ole" <ol*@blabla.comwrote in message
news:er**************@TK2MSFTNGP02.phx.gbl...

>Hi,

I have an instance of a class in which a thread is running. When a
special condition in that instance is met it raises an event to my main
class (UI), but I can't directly interact with the user interface
controls in my eventhandler without some sort of invoke. How should that
be done - is it possible to locate the invoke in the instance so that the
eventhandler actually belongs to the UI?

Thanks,
Ole