How getting eventhandler attached to an event?

6 May 2006 9:19 AM

Carlo (mcp)

Good morning

I have this lines:

          AddHandler MyControl1.Parent.Paint, AddressOf PaintParentHandler
          AddHandler MyControl2.Parent.Paint, AddressOf PaintParentHandler
          AddHandler MyControl3.Parent.Paint, AddressOf PaintParentHandler
          AddHandler MyControl4.Parent.Paint, AddressOf PaintParentHandler
          AddHandler MyControl5.Parent.Paint, AddressOf PaintParentHandler

Is there a way for getting (at runtime) the list of eventhandlers attached
to an event? In my case, a reference to PaintParentHandler?

Since MyControl1, MyControl2, MyControl3, MyControl4 and MyControl5 are
inside the SAME parent, I need this in order to avoid multiple (useless)
calls to PaintParentHandler.

Thank you.

C.

-------------------------------------------
Carlo, MCP (Windows Based Applications)
carlodevREM***@gmail.com

7 May 2006 12:48 AM

Duane Phillips

Rather than go through all that, can you use a static or global variable to
lock out successive semi-concurrent attempts?

For example:

"
SUB EVENTHANDLER()
STATIC blnIsRunning as boolean
If blnIsRunning then Return
blnIsRunning = True
'remainder of code execution for this handler
blnIsRunning = False
END SUB
"
- or -

"
PUBLIC blnIsRunning as boolean 'a PRIVATE dimension may be more
appropriate...

SUB EVENTHANDLER()
If blnIsRunning then Return
blnIsRunning = True
'remainder of code execution for this handler
blnIsRunning = False
END SUB
"

Cheers!

~ Duane Phillips

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"Carlo (mcp)" <carlodevREM***@gmail.com> wrote in message
news:eO7Lp4OcGHA.1856@TK2MSFTNGP03.phx.gbl...
> Good morning
>
> I have this lines:
>
>          AddHandler MyControl1.Parent.Paint, AddressOf PaintParentHandler
>          AddHandler MyControl2.Parent.Paint, AddressOf PaintParentHandler
>          AddHandler MyControl3.Parent.Paint, AddressOf PaintParentHandler
>          AddHandler MyControl4.Parent.Paint, AddressOf PaintParentHandler
>          AddHandler MyControl5.Parent.Paint, AddressOf PaintParentHandler
>
> Is there a way for getting (at runtime) the list of eventhandlers attached
> to an event? In my case, a reference to PaintParentHandler?
>
> Since MyControl1, MyControl2, MyControl3, MyControl4 and MyControl5 are
> inside the SAME parent, I need this in order to avoid multiple (useless)
> calls to PaintParentHandler.
>
> Thank you.
>
> C.
>
>
>
> -------------------------------------------
> Carlo, MCP (Windows Based Applications)
> carlodevREM***@gmail.com
>
>
>

7 May 2006 6:39 AM

Carlo (mcp)

Hi Duane
thank you for your suggestion. Unfortunately, it doen not applies to my
case. I don't need to avoid the concurrent execution of a procedure. I
simply need to have just one procedure attached to an event. What I need, in
other words, is a single call to AddHandler, if a handler is already set.
Thank you.

--

-------------------------------------------
Carlo, MCP (Windows Based Applications)
carlodevREM***@gmail.com

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"Duane Phillips" <duane.phillips@askme.askme> wrote in message
news:wNqdnZ1JBoZR3sDZnZ2dnUVZ_vOdnZ2d@giganews.com...
> Rather than go through all that, can you use a static or global variable
> to lock out successive semi-concurrent attempts?
>
> For example:
>
> "
> SUB EVENTHANDLER()
> STATIC blnIsRunning as boolean
> If blnIsRunning then Return
> blnIsRunning = True
> 'remainder of code execution for this handler
> blnIsRunning = False
> END SUB
> "
> - or -
>
> "
> PUBLIC blnIsRunning as boolean 'a PRIVATE dimension may be more
> appropriate...
>
> SUB EVENTHANDLER()
> If blnIsRunning then Return
> blnIsRunning = True
> 'remainder of code execution for this handler
> blnIsRunning = False
> END SUB
> "
>
> Cheers!
>
> ~ Duane Phillips
>
> "Carlo (mcp)" <carlodevREM***@gmail.com> wrote in message
> news:eO7Lp4OcGHA.1856@TK2MSFTNGP03.phx.gbl...
>> Good morning
>>
>> I have this lines:
>>
>>          AddHandler MyControl1.Parent.Paint, AddressOf PaintParentHandler
>>          AddHandler MyControl2.Parent.Paint, AddressOf PaintParentHandler
>>          AddHandler MyControl3.Parent.Paint, AddressOf PaintParentHandler
>>          AddHandler MyControl4.Parent.Paint, AddressOf PaintParentHandler
>>          AddHandler MyControl5.Parent.Paint, AddressOf PaintParentHandler
>>
>> Is there a way for getting (at runtime) the list of eventhandlers
>> attached to an event? In my case, a reference to PaintParentHandler?
>>
>> Since MyControl1, MyControl2, MyControl3, MyControl4 and MyControl5 are
>> inside the SAME parent, I need this in order to avoid multiple (useless)
>> calls to PaintParentHandler.
>>
>> Thank you.
>>
>> C.
>>
>>
>>
>> -------------------------------------------
>> Carlo, MCP (Windows Based Applications)
>> carlodevREM***@gmail.com
>>
>>
>>
>
>

8 May 2006 7:43 AM

R. MacDonald

Hello, Carlo,

You might be able to get the information you need by iterating through
the collection returned by MyControln.Parent.GetType.GetEvents(). Look
for a case where the Name property of the matches "Paint".

Cheers,
Randy

Carlo (mcp) wrote:
Show quoteHide quote

> Good morning
>
> I have this lines:
>
>           AddHandler MyControl1.Parent.Paint, AddressOf PaintParentHandler
>           AddHandler MyControl2.Parent.Paint, AddressOf PaintParentHandler
>           AddHandler MyControl3.Parent.Paint, AddressOf PaintParentHandler
>           AddHandler MyControl4.Parent.Paint, AddressOf PaintParentHandler
>           AddHandler MyControl5.Parent.Paint, AddressOf PaintParentHandler
>
> Is there a way for getting (at runtime) the list of eventhandlers attached
> to an event? In my case, a reference to PaintParentHandler?
>
> Since MyControl1, MyControl2, MyControl3, MyControl4 and MyControl5 are
> inside the SAME parent, I need this in order to avoid multiple (useless)
> calls to PaintParentHandler.
>
> Thank you.
>
> C.
>
>
>
> -------------------------------------------
> Carlo, MCP (Windows Based Applications)
> carlodevREM***@gmail.com
>
>
>

8 May 2006 10:01 AM

Larry Lard

Carlo (mcp) wrote:

> Good morning
>
> I have this lines:
>
>           AddHandler MyControl1.Parent.Paint, AddressOf PaintParentHandler
>           AddHandler MyControl2.Parent.Paint, AddressOf PaintParentHandler
>           AddHandler MyControl3.Parent.Paint, AddressOf PaintParentHandler
>           AddHandler MyControl4.Parent.Paint, AddressOf PaintParentHandler
>           AddHandler MyControl5.Parent.Paint, AddressOf PaintParentHandler
>
> Is there a way for getting (at runtime) the list of eventhandlers attached
> to an event? In my case, a reference to PaintParentHandler?

No. The list of event subscribers is a proivate implementation detail
of the Control. It doens't have to tell you who is subscribed.

>
> Since MyControl1, MyControl2, MyControl3, MyControl4 and MyControl5 are
> inside the SAME parent, I need this in order to avoid multiple (useless)
> calls to PaintParentHandler.

Rough method:

- keep a list of controls
- for each MyControl
-     is MyControl.Parent in the list?
-         if it is, then we are already hooked to its paint event, so
do nothing
-         if it isn't, then hook to its Paint event, and add it to the
list

--
Larry Lard
Replies to group please

18 May 2006 1:10 PM

Carlo (mcp)

Sorry for the delay in saying thank you to the people that replied me!
Carlo

--

-------------------------------------------
Carlo, MCP (Windows Based Applications)
carlodevREM***@gmail.com

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"Larry Lard" <larryl***@hotmail.com> wrote in message
news:1147082464.234824.128920@g10g2000cwb.googlegroups.com...
>
> Carlo (mcp) wrote:
>> Good morning
>>
>> I have this lines:
>>
>>           AddHandler MyControl1.Parent.Paint, AddressOf
>> PaintParentHandler
>>           AddHandler MyControl2.Parent.Paint, AddressOf
>> PaintParentHandler
>>           AddHandler MyControl3.Parent.Paint, AddressOf
>> PaintParentHandler
>>           AddHandler MyControl4.Parent.Paint, AddressOf
>> PaintParentHandler
>>           AddHandler MyControl5.Parent.Paint, AddressOf
>> PaintParentHandler
>>
>> Is there a way for getting (at runtime) the list of eventhandlers
>> attached
>> to an event? In my case, a reference to PaintParentHandler?
>
> No. The list of event subscribers is a proivate implementation detail
> of the Control. It doens't have to tell you who is subscribed.
>
>>
>> Since MyControl1, MyControl2, MyControl3, MyControl4 and MyControl5 are
>> inside the SAME parent, I need this in order to avoid multiple (useless)
>> calls to PaintParentHandler.
>
> Rough method:
>
> - keep a list of controls
> - for each MyControl
> -     is MyControl.Parent in the list?
> -         if it is, then we are already hooked to its paint event, so
> do nothing
> -         if it isn't, then hook to its Paint event, and add it to the
> list
>
>
> --
> Larry Lard
> Replies to group please
>