Global Events that all instances of a control handles

[Phil]

I have a user control (called MyControl that inherits from
CompositeControl). This control will raise an event when the user changes
the color of the control. (MyControl.ColorChange). Inside the code for
MyControl, I also listen and handle the event (ColorChange). - This actually
implements the change in color. This works OK for the control that raised
the event.

However, in the aspx form, I have 5 instances of the same user control
(MyControl). When one of the controls change color (based on user input) I
would like to have each instance of the MyControl listen for the event and
handle the ChangeColor event. When I try this only the control that raised
the event will hear the event. Is there any way to globally raise an event
that all controls could listen too?

Thanks

Phil

[Phil]

I have a user control (called MyControl that inherits from
CompositeControl). This control will raise an event when the user changes
the color of the control. (MyControl.ColorChange). Inside the code for
MyControl, I also listen and handle the event (ColorChange). - This actually
implements the change in color. This works OK for the control that raised
the event.

However, in the aspx form, I have 5 instances of the same user control
(MyControl). When one of the controls change color (based on user input) I
would like to have each instance of the MyControl listen for the event and
handle the ChangeColor event. When I try this only the control that raised
the event will hear the event. Is there any way to globally raise an event
that all controls could listen too?

Thanks

Phil

[RLJ]

On 2006-09-11 02:03:52 -0500, "Phil" <lynch_15@hotmail.com> said:

> I have a user control (called MyControl that inherits from
> CompositeControl). This control will raise an event when the user
> changes the color of the control. (MyControl.ColorChange). Inside the
> code for MyControl, I also listen and handle the event (ColorChange). -
> This actually implements the change in color. This works OK for the
> control that raised the event.
>
> However, in the aspx form, I have 5 instances of the same user control
> (MyControl). When one of the controls change color (based on user
> input) I would like to have each instance of the MyControl listen for
> the event and handle the ChangeColor event. When I try this only the
> control that raised the event will hear the event. Is there any way to
> globally raise an event that all controls could listen too?
>
> Thanks
>
> Phil
>

In the user control
* Define a Delegate
* Define an event based on the delegate
* Fire the event

In the "listener" controls
* subscribe to the event
* write an event handler
* "wire" the event handler to the delegate

/*************** Event Publisher ****************/
public PublisherClass { // the class that changed it's color
pubic delegate void myDelegate(string newColor);
public event myDelegate myEvent;

// "wire" this method to the OnChange property of your Select listbox.
private void OnColorChange(string theNewColor) {
this.myEvent();
}
}


/*********** meanwhile, in the listener contols' code ***********/
public ListenerClass {
PublisherClass myPublisher = new PublisherClass();

override protected void OnInit (EventArgs e) {
myPublisher.myEvent += myPublisher.myDelegate(ChangeMyColor);
}

public void ChangeMyColor (string newColor) {
// change the color to newColor
}
}

/************ Caveat **************/
If you want every control to listen to every other control's
ChangeColor event then I'm not sure
how to neatly implement that. I guess every control will be both a
publisher and subscriber - sounds cool, if it works - Either every
control defines it's own event and all controls subscribe to all other
control's events.. OR .. here's something wacky: think it *could* go
like this (WARNING: wild-ass guess follows):
* Define the delegate and event at the namespace level (i.e. at the
container page level?)
* Each control will have an OnChange handler for what I assume is a
drop-down select list of colors
* In that OnChange handler of every control, call the event
* in OnInit() of every control set "this.myEvent +=
this.myDelegate(ChangeMyColor)" (not too sure that "this" will cut it)
* so the drop-down list event handler fires the event and a separate
method (wired to the delegate) does the actual work
***** would this cause an infinite loop?

[Phil]

Thanks for the response. I managed a workaround, but your suggestions is
much neater. Will try to implement it this way!


"RLJ" <robert@joneshouse.com> wrote in message
news:2006100101400043658-robert@joneshousecom...

> On 2006-09-11 02:03:52 -0500, "Phil" <lynch_15@hotmail.com> said:
>

>> I have a user control (called MyControl that inherits from
>> CompositeControl). This control will raise an event when the user
>> changes the color of the control. (MyControl.ColorChange). Inside the
>> code for MyControl, I also listen and handle the event (ColorChange). -
>> This actually implements the change in color. This works OK for the
>> control that raised the event.
>>
>> However, in the aspx form, I have 5 instances of the same user control
>> (MyControl). When one of the controls change color (based on user input)
>> I would like to have each instance of the MyControl listen for the event
>> and handle the ChangeColor event. When I try this only the control that
>> raised the event will hear the event. Is there any way to globally raise
>> an event that all controls could listen too?
>>
>> Thanks
>>
>> Phil
>>

> In the user control
> * Define a Delegate
> * Define an event based on the delegate
> * Fire the event
>
> In the "listener" controls
> * subscribe to the event
> * write an event handler
> * "wire" the event handler to the delegate
>
> /*************** Event Publisher ****************/
> public PublisherClass { // the class that changed it's color
> pubic delegate void myDelegate(string newColor);
> public event myDelegate myEvent;
>
> // "wire" this method to the OnChange property of your Select
> listbox.
> private void OnColorChange(string theNewColor) {
> this.myEvent();
> }
> }
>
>
> /*********** meanwhile, in the listener contols' code ***********/
> public ListenerClass {
> PublisherClass myPublisher = new PublisherClass();
>
> override protected void OnInit (EventArgs e) {
> myPublisher.myEvent += myPublisher.myDelegate(ChangeMyColor);
> }
>
> public void ChangeMyColor (string newColor) {
> // change the color to newColor
> }
> }
>
> /************ Caveat **************/
> If you want every control to listen to every other control's ChangeColor
> event then I'm not sure
> how to neatly implement that. I guess every control will be both a
> publisher and subscriber - sounds cool, if it works - Either every control
> defines it's own event and all controls subscribe to all other control's
> events.. OR .. here's something wacky: think it *could* go like this
> (WARNING: wild-ass guess follows):
> * Define the delegate and event at the namespace level (i.e. at the
> container page level?)
> * Each control will have an OnChange handler for what I assume is a
> drop-down select list of colors
> * In that OnChange handler of every control, call the event
> * in OnInit() of every control set "this.myEvent +=
> this.myDelegate(ChangeMyColor)" (not too sure that "this" will cut it)
> * so the drop-down list event handler fires the event and a separate
> method (wired to the delegate) does the actual work
> ***** would this cause an infinite loop?
>
>