Re: any way to suspend events for controls while I edit them?

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Oh i see!

So he wants the event to not fire when his CODE changes the value not HIM as
a person clicking as it implied before. I get it now.

Umm, for a list box for the user to change the value they would have to
first click the mouse button or some other input key right? Could you not
make a new control that inherits from the listbox control, and have the
boolean set by that mouse click? Or something similar to distinguish a user
change over your own? That would be one way of a generic way of reading the
user, which would allow a control that only fires that even on a user change
as oppose to a code change of the value.

It all depends on the timing of the event si guess. Does the event fire
once a user has highlightes a new option and clicks the mouse on it?
Similarly does it fire if they press the up or down key when the control has
focus?

You could use focus as a check, override the selection changed event in your
inherited control to say if has focus and mouse clicked or key pressed then
user change so fire event for change made and pass vars in. Otherwise dont
fire event. Would that work?



"Bruce Wood" <brucewood@xxxxxxxxxx> wrote in message
news:1160072972.695553.136260@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Setting the bool is simple. To understand how it works, you have to go
back to the original problem, which restated, looks like this:

"Have event handlers that I want to invoke whenever the user
manipulates a control, but I don't want to invoke them when I
manipulate the control from within my program."

Unfortunately, the .NET framework doesn't provide a mechanism for
distinguishing between events that result from user actions from events
that result from you messing with the controls in your program. Cue the
boolean.

All you do is create a boolean in your class:

private bool _programIsChangingControls = false;

Then, whenever you write some code that populates a ComboBox, or
changes check boxes in a ListView, or something like that, you do this:

private void SomeFunction()
{
this._programIsChangingControls = true;
this.comboBox1.SelectedItem = ... ;
this._programIsChangingControls = false;
}

and then, in your event handler:

private void comboBox1_SelectedIndexChanged(void sender,
System.EventArgs e)
{
if (!this._programIsChangingControls)
{
... handle the event ...
}
}

I do the same sort of thing with validation routines: unfortunately the
Framework doesn't provide a way to cancel pending validation events, so
I just create a flag that tells the event handlers to not bother
validating, then when I need to flush validation events I set the flag,
force validation, and unset the flag.

Daniel wrote:
I have to add, i am with Mythran, i am confused by this also but 'boing
with
the flow' my other answer is stil how i would do it. Tho as i was writing
it
i was thinking i have no idea how you will set that bool that you changed
the data. But anyway.....


"Daniel" <DanielV@xxxxxxxxxxxxxxxx> wrote in message
news:%23BUTXbK6GHA.4608@xxxxxxxxxxxxxxxxxxxxxxx
by using a drop down like that have you thought of making a new type of
drop down that reacts differently?

So like

class EditDropDown : DropDownList

and then change that drop down to react differently in the
circumstances.
So you could override the event handler to pass the boolean value that
it
was changed by you or not by you. Allowing your code using it to be
much
neater but using the same methodology. Then the control itself could do
all the working out for you, you just check the boolean. Make sense?


"MrNobody" <MrNobody@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
news:67333537-D7A8-472D-BF15-68C81DF9515A@xxxxxxxxxxxxxxxx
If I have a control like say a drop down list and I have some kind of
onSelectItem change event, is there a way to temporarily suspend the
event
handling (without removing the event and then re-attaching it?) while
I
edit
it's contents which would otherwise cause the event to fire?

Or is there maybe a way in my event handler to tell if the user
triggered
it
as opposed to the program itself?





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