Event Reflection

[BK]

Hi,

I have a class which has a lot of events (>100). For some reasons, I have to
go through all invocation lists to do something. What I'm wondering is that,
is there any way to use reflection to get their InvocationList without going
through each event?

// tedious
foreach (Delegate handler in Event1.GetInvoc ationList()) {...}
foreach (Delegate handler in Event2.GetInvoc ationList()) {...}
foreach (Delegate handler in Event3.GetInvoc ationList()) {...}
....
foreach (Delegate handler in Event189.GetInv ocationList()) {...}

// user reflection???
.....

Looks like this is a hard question as I haven't googled any answers. Thanks

BK

[Greg Ewing [MVP]]

Re: Event Reflection

BK, I don't understand what you are trying to do. What do you want that
GetInvocationLi st() doesn't give you?

--
Greg Ewing [MVP]

http://www.citidc.com

"BK" <bluekiteNO-SPAM@rogers.com > wrote in message
news:eGq6N8WeDH A.696@TK2MSFTNG P09.phx.gbl...[color=blue]
> Hi,
>
> I have a class which has a lot of events (>100). For some reasons, I have[/color]
to[color=blue]
> go through all invocation lists to do something. What I'm wondering is[/color]
that,[color=blue]
> is there any way to use reflection to get their InvocationList without[/color]
going[color=blue]
> through each event?
>
> // tedious
> foreach (Delegate handler in Event1.GetInvoc ationList()) {...}
> foreach (Delegate handler in Event2.GetInvoc ationList()) {...}
> foreach (Delegate handler in Event3.GetInvoc ationList()) {...}
> ...
> foreach (Delegate handler in Event189.GetInv ocationList()) {...}
>
> // user reflection???
> ....
>
> Looks like this is a hard question as I haven't googled any answers.[/color]
Thanks[color=blue]
>
> BK
>
>[/color]

[John Saunders]

Re: Event Reflection

"BK" <bluekiteNO-SPAM@rogers.com > wrote in message
news:eGq6N8WeDH A.696@TK2MSFTNG P09.phx.gbl...[color=blue]
> Hi,
>
> I have a class which has a lot of events (>100). For some reasons, I have[/color]
to[color=blue]
> go through all invocation lists to do something. What I'm wondering is[/color]
that,[color=blue]
> is there any way to use reflection to get their InvocationList without[/color]
going[color=blue]
> through each event?[/color]

Are you aware of the alternate way to declare events?

public event EventHandler Something
{
add {add "value" to some list}
remove {remove "value" from the list}
}

The System.Web.UI.C ontrol class defines its events this way. It also
declares an "Events" property of type EventHandlerLis t. The EventHandlerLis t
class defines AddHandler and RemoveHandler methods, and an indexer. These
all take an arbitrary object as a parameter:

private static readonly object SomeEvent = new object();

public event EventHandler Something
{
add
{
Events.AddHandl er(SomeEvent, value);
}
remove
{
Events.RemoveHa ndler(SomeEvent , value);
}
}

protected virtual void OnSomething(Eve ntArgs e)
{
EventHandler someEventDelega te = (EventHandler) Events[SomeEvent];
if (someEventDeleg ate != null)
someEventDelega te(this, e);
}

Now, it seems to me that you could do something similar, perhaps using a
HashTable instead of an EventHandlerLis t. You would then be able to iterate
over the hashtable and access each event handler in the loop.
--
John Saunders
Internet Engineer
john.saunders@s urfcontrol.com

}

[Eric Gunnerson [MS]]

Re: Event Reflection

Sure:

Type type = typeof (YourClassName) ; // can use instance.GetTyp e()
as well.

foreach (MemberInfo memberInfo in type.GetMembers ())
{
if (memberInfo.Mem berType == MemberType.Even t)

// and then you use MemberType to get the value here. It will probably
come back as as a delegate (I'm not sure).
}

Hope that helps.



--
Eric Gunnerson

Visit the C# product team at http://www.csharp.net
Eric's blog is at http://blogs.gotdotnet.com/ericgu/

This posting is provided "AS IS" with no warranties, and confers no rights.
"BK" <bluekiteNO-SPAM@rogers.com > wrote in message
news:eGq6N8WeDH A.696@TK2MSFTNG P09.phx.gbl...[color=blue]
> Hi,
>
> I have a class which has a lot of events (>100). For some reasons, I have[/color]
to[color=blue]
> go through all invocation lists to do something. What I'm wondering is[/color]
that,[color=blue]
> is there any way to use reflection to get their InvocationList without[/color]
going[color=blue]
> through each event?
>
> // tedious
> foreach (Delegate handler in Event1.GetInvoc ationList()) {...}
> foreach (Delegate handler in Event2.GetInvoc ationList()) {...}
> foreach (Delegate handler in Event3.GetInvoc ationList()) {...}
> ...
> foreach (Delegate handler in Event189.GetInv ocationList()) {...}
>
> // user reflection???
> ....
>
> Looks like this is a hard question as I haven't googled any answers.[/color]
Thanks[color=blue]
>
> BK
>
>[/color]

[BK]

Re: Event Reflection

Yes, I tried this, but there is no way to get the value of event delegate.

"Eric Gunnerson [MS]" <ericgu@online. microsoft.com> wrote in message
news:#nKaIileDH A.1836@TK2MSFTN GP09.phx.gbl...[color=blue]
> Sure:
>
> Type type = typeof (YourClassName) ; // can use[/color]
instance.GetTyp e()[color=blue]
> as well.
>
> foreach (MemberInfo memberInfo in type.GetMembers ())
> {
> if (memberInfo.Mem berType == MemberType.Even t)
>
> // and then you use MemberType to get the value here. It will probably
> come back as as a delegate (I'm not sure).
> }
>
> Hope that helps.
>
>
>
> --
> Eric Gunnerson
>
> Visit the C# product team at http://www.csharp.net
> Eric's blog is at http://blogs.gotdotnet.com/ericgu/
>
> This posting is provided "AS IS" with no warranties, and confers no[/color]
rights.[color=blue]
> "BK" <bluekiteNO-SPAM@rogers.com > wrote in message
> news:eGq6N8WeDH A.696@TK2MSFTNG P09.phx.gbl...[color=green]
> > Hi,
> >
> > I have a class which has a lot of events (>100). For some reasons, I[/color][/color]
have[color=blue]
> to[color=green]
> > go through all invocation lists to do something. What I'm wondering is[/color]
> that,[color=green]
> > is there any way to use reflection to get their InvocationList without[/color]
> going[color=green]
> > through each event?
> >
> > // tedious
> > foreach (Delegate handler in Event1.GetInvoc ationList()) {...}
> > foreach (Delegate handler in Event2.GetInvoc ationList()) {...}
> > foreach (Delegate handler in Event3.GetInvoc ationList()) {...}
> > ...
> > foreach (Delegate handler in Event189.GetInv ocationList()) {...}
> >
> > // user reflection???
> > ....
> >
> > Looks like this is a hard question as I haven't googled any answers.[/color]
> Thanks[color=green]
> >
> > BK
> >
> >[/color]
>
>[/color]

[BK]

Re: Event Reflection

Basically, I want to get the value of each event delegate using its name
string, like "event1", instead of going through each event to do something
the same, which is very tedious.

Thanks,

"Greg Ewing [MVP]" <gewing@_NO_SPA M_gewing.com> wrote in message
news:#XQX4SXeDH A.3788@tk2msftn gp13.phx.gbl...[color=blue]
> BK, I don't understand what you are trying to do. What do you want that
> GetInvocationLi st() doesn't give you?
>
> --
> Greg Ewing [MVP]
> http://www.citidc.com
>
> "BK" <bluekiteNO-SPAM@rogers.com > wrote in message
> news:eGq6N8WeDH A.696@TK2MSFTNG P09.phx.gbl...[color=green]
> > Hi,
> >
> > I have a class which has a lot of events (>100). For some reasons, I[/color][/color]
have[color=blue]
> to[color=green]
> > go through all invocation lists to do something. What I'm wondering is[/color]
> that,[color=green]
> > is there any way to use reflection to get their InvocationList without[/color]
> going[color=green]
> > through each event?
> >
> > // tedious
> > foreach (Delegate handler in Event1.GetInvoc ationList()) {...}
> > foreach (Delegate handler in Event2.GetInvoc ationList()) {...}
> > foreach (Delegate handler in Event3.GetInvoc ationList()) {...}
> > ...
> > foreach (Delegate handler in Event189.GetInv ocationList()) {...}
> >
> > // user reflection???
> > ....
> >
> > Looks like this is a hard question as I haven't googled any answers.[/color]
> Thanks[color=green]
> >
> > BK
> >
> >[/color]
>
>[/color]