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dropdownlist bug?

I have a web form in which I'm selecting values of 10 different dropdownlists using a for each. I use DirectCast along with FindControl to get each dropdown and set the value. It seems that setting the SelectedIndex of the variable referencing my DropDownList changes the selectedindex of the 9 other dropdowns to match so the same SelectedIndex is set for every dropdown. I've stepped through, and I know the code is not setting the same selectedindex every time. The sp object referenced in my code below is a custom class that allows me to match up values to the list. IN the example below, sp.Attribute might = "VAL_1" which would result in finding a listitem with a value of "VAL_1

Here is the code
Dim ddlAttribute as DropDownLis
i=
For each sp in param
i+=
ddlAttribute = DirectCast(FindControl("ddlSearchAtt_" & i),DropDownList
ddlAttribute.SelectedIndex = ddlAttribute.Items.IndexOf(ddlAttribute.Items.Find ByValue(sp.Attribute)
Nex

thanks in advanc
sk
Nov 18 '05 #1
4 1142
It's not a bug.

FindControl returns a reference to a control. This is one memory address
where a control resides. You take this one reference and you add it to 9
places. Then, you say to this one reference, which is found in 9 places, put
a selectedindex attribute on yourself. So it does. But, remember there are 9
other places where this reference is found all pointing back to this one
area in memory which represents a control so the 9 places have no choice but
to reflect what ever the control does. makes sense?
Here is what it looks like diagramatically

- - - - - - - - -
|
______|_______
|control selection|
-----------------

What you are probably after is to make a new control for every pass of the
loop.
--
Regards,
Alvin Bruney [ASP.NET MVP]
Got tidbits? Get it here...
http://tinyurl.com/3he3b
"skyking1" <an*******@discussions.microsoft.com> wrote in message
news:52**********************************@microsof t.com...
I have a web form in which I'm selecting values of 10 different dropdownlists using a for each. I use DirectCast along with FindControl to
get each dropdown and set the value. It seems that setting the SelectedIndex
of the variable referencing my DropDownList changes the selectedindex of the
9 other dropdowns to match so the same SelectedIndex is set for every
dropdown. I've stepped through, and I know the code is not setting the same
selectedindex every time. The sp object referenced in my code below is a
custom class that allows me to match up values to the list. IN the example
below, sp.Attribute might = "VAL_1" which would result in finding a listitem
with a value of "VAL_1"
Here is the code:
Dim ddlAttribute as DropDownList
i=0
For each sp in params
i+=1
ddlAttribute = DirectCast(FindControl("ddlSearchAtt_" & i),DropDownList)
ddlAttribute.SelectedIndex = ddlAttribute.Items.IndexOf(ddlAttribute.Items.Find ByValue(sp.Attribute)) Next
thanks in advance
sk

Nov 18 '05 #2
I'm trying to get my hands around what you are saying, but having trouble

Since the form is designed with 10 controls,ddlSearchAtt_1,_2,_3 etc, how is it that findcontrol("ddlSearchAtt_1") and findControl("ddlSearchAtt_2") are returning a reference to the same object

Are you just saying that I need to "redeclare" my ddlAttribute object as new for each iteration of the loop and that should fix it

Thanks alot for your help, this has been killing me.
Nov 18 '05 #3
yes

--
Regards,
Alvin Bruney [ASP.NET MVP]
Got tidbits? Get it here...
http://tinyurl.com/3he3b
"skyking1" <an*******@discussions.microsoft.com> wrote in message
news:B1**********************************@microsof t.com...
I'm trying to get my hands around what you are saying, but having trouble.

Since the form is designed with 10 controls,ddlSearchAtt_1,_2,_3 etc, how is it that findcontrol("ddlSearchAtt_1") and findControl("ddlSearchAtt_2")
are returning a reference to the same object?
Are you just saying that I need to "redeclare" my ddlAttribute object as new for each iteration of the loop and that should fix it.
Thanks alot for your help, this has been killing me.

Nov 18 '05 #4
Interesting. Still doesn't work. I even changed the code to do this

Me.ddlSearchAtt_1.SelectedIndex =
Me.ddlSearchAtt_2.SelectedIndex =

When this code runs, all SelectedIndexes are changed to 4. Any other ideas?
Nov 18 '05 #5

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