Get DropDownList.Se lectedValue from Page_PreInit Event

[Redhairs]

Is it possible to get DropDownList.Se lectedValue in Page_PreInit() event
during the postback?

[=?Utf-8?B?Q2hhZCBTY2hhcmY=?=]

Unfortunately I believe the answer is no. Is there a reason you need this
value before the page is initialized?

You could potentially inject the value into a cookie using JavaScript using
the OnSubmit event of your form, then read that using the
HttpContext.Cur rent.Request.Co okies collection to retrieve your value upon
post-back. I believe the HttpRequest stack has been created by then and upon
calling the OnPreInit method of your page, has built these values from the
request headers.

--
Chad Scharf
_______________ _______________ _
http://www.chadscharf.com
"Redhairs" wrote:

Is it possible to get DropDownList.Se lectedValue in Page_PreInit() event
during the postback?

[=?Utf-8?B?TWlsb3N6IFNrYWxlY2tpIFtNQ0FEXQ==?=]

Howdy,

Why using cookie, wouldn't be easier just by using
string selectedValue = Request.Form[yourDropDown.Un iqueID]
?
--
Milosz
"Chad Scharf" wrote:

Unfortunately I believe the answer is no. Is there a reason you need this
value before the page is initialized?

You could potentially inject the value into a cookie using JavaScript using
the OnSubmit event of your form, then read that using the
HttpContext.Cur rent.Request.Co okies collection to retrieve your value upon
post-back. I believe the HttpRequest stack has been created by then and upon
calling the OnPreInit method of your page, has built these values from the
request headers.

--
Chad Scharf
_______________ _______________ _
http://www.chadscharf.com
"Redhairs" wrote:

Is it possible to get DropDownList.Se lectedValue in Page_PreInit() event
during the postback?

[=?Utf-8?B?Q2hhZCBTY2hhcmY=?=]

Yes, that would be easier. Sorry, I typically never use Request.Form and
forgot about it.

Is the UniqueID available though in the Page_PreInit event, seeing as the
control tree has not yet been built, it would be difficult for the Page to
calculate the UniqueID, and typically the Control instance would be null as
well no?

--
Chad Scharf
_______________ _______________ _
http://www.chadscharf.com
"Milosz Skalecki [MCAD]" wrote:

Howdy,

Why using cookie, wouldn't be easier just by using
string selectedValue = Request.Form[yourDropDown.Un iqueID]
?
--
Milosz
"Chad Scharf" wrote:

Unfortunately I believe the answer is no. Is there a reason you need this
value before the page is initialized?

You could potentially inject the value into a cookie using JavaScript using
the OnSubmit event of your form, then read that using the
HttpContext.Cur rent.Request.Co okies collection to retrieve your value upon
post-back. I believe the HttpRequest stack has been created by then and upon
calling the OnPreInit method of your page, has built these values from the
request headers.

--
Chad Scharf
_______________ _______________ _
http://www.chadscharf.com
"Redhairs" wrote:

Is it possible to get DropDownList.Se lectedValue in Page_PreInit() event
during the postback?
>
>
>

[=?Utf-8?B?TWlsb3N6IFNrYWxlY2tpIFtNQ0FEXQ==?=]

Hi Chad,

The control tree is already created in PreInit event, as the aspx page
compiler puts all the declarations into FrameworkInitia lize() method which is
called from Page.ProcessReq uest (member of the IHttpHandler interface) (have
a look at the content of your website's asp.net folder, especially at
compiled pages). Therefore, it's safe to run the code:
Request.Form[ddl.uniqueID]

Regards
--
Milosz
"Chad Scharf" wrote:

Yes, that would be easier. Sorry, I typically never use Request.Form and
forgot about it.

Is the UniqueID available though in the Page_PreInit event, seeing as the
control tree has not yet been built, it would be difficult for the Page to
calculate the UniqueID, and typically the Control instance would be null as
well no?

--
Chad Scharf
_______________ _______________ _
http://www.chadscharf.com
"Milosz Skalecki [MCAD]" wrote:

Howdy,

Why using cookie, wouldn't be easier just by using
string selectedValue = Request.Form[yourDropDown.Un iqueID]
?
--
Milosz
"Chad Scharf" wrote:

Unfortunately I believe the answer is no. Is there a reason you need this
value before the page is initialized?
>
You could potentially inject the value into a cookie using JavaScript using
the OnSubmit event of your form, then read that using the
HttpContext.Cur rent.Request.Co okies collection to retrieve your value upon
post-back. I believe the HttpRequest stack has been created by then and upon
calling the OnPreInit method of your page, has built these values from the
request headers.
>
--
Chad Scharf
_______________ _______________ _
http://www.chadscharf.com
>
>
"Redhairs" wrote:
>
Is it possible to get DropDownList.Se lectedValue in Page_PreInit() event
during the postback?

[Redhairs]

It doesn't work and return error msg "Object reference not set to an
instance of an object"
"Milosz Skalecki [MCAD]" <mi*****@DONTLI KESPAMwp.plwrot e in message
news:EF******** *************** ***********@mic rosoft.com...

Hi Chad,

The control tree is already created in PreInit event, as the aspx page
compiler puts all the declarations into FrameworkInitia lize() method which
is
called from Page.ProcessReq uest (member of the IHttpHandler interface)
(have
a look at the content of your website's asp.net folder, especially at
compiled pages). Therefore, it's safe to run the code:
Request.Form[ddl.uniqueID]

Regards
--
Milosz
"Chad Scharf" wrote:

>Yes, that would be easier. Sorry, I typically never use Request.Form and
forgot about it.

Is the UniqueID available though in the Page_PreInit event, seeing as the
control tree has not yet been built, it would be difficult for the Page
to
calculate the UniqueID, and typically the Control instance would be null
as
well no?

--
Chad Scharf
______________ _______________ __
http://www.chadscharf.com
"Milosz Skalecki [MCAD]" wrote:

Howdy,

Why using cookie, wouldn't be easier just by using
string selectedValue = Request.Form[yourDropDown.Un iqueID]
?
--
Milosz
"Chad Scharf" wrote:

Unfortunately I believe the answer is no. Is there a reason you need
this
value before the page is initialized?

You could potentially inject the value into a cookie using JavaScript
using
the OnSubmit event of your form, then read that using the
HttpContext.Cur rent.Request.Co okies collection to retrieve your value
upon
post-back. I believe the HttpRequest stack has been created by then
and upon
calling the OnPreInit method of your page, has built these values
from the
request headers.

--
Chad Scharf
_______________ _______________ _
http://www.chadscharf.com
"Redhairs" wrote:

Is it possible to get DropDownList.Se lectedValue in Page_PreInit()
event
during the postback?

[=?Utf-8?B?TWlsb3N6IFNrYWxlY2tpIFtNQ0FEXQ==?=]

Hi Redhairs,

I checked it and it works fine. Are you by any chance create this control
dynamically or drop down list is placed inside a tamplated control? Could you
please pase some code?

Regards
--
Milosz
"Redhairs" wrote:

It doesn't work and return error msg "Object reference not set to an
instance of an object"
"Milosz Skalecki [MCAD]" <mi*****@DONTLI KESPAMwp.plwrot e in message
news:EF******** *************** ***********@mic rosoft.com...

Hi Chad,

The control tree is already created in PreInit event, as the aspx page
compiler puts all the declarations into FrameworkInitia lize() method which
is
called from Page.ProcessReq uest (member of the IHttpHandler interface)
(have
a look at the content of your website's asp.net folder, especially at
compiled pages). Therefore, it's safe to run the code:
Request.Form[ddl.uniqueID]

Regards
--
Milosz
"Chad Scharf" wrote:

Yes, that would be easier. Sorry, I typically never use Request.Form and
forgot about it.

Is the UniqueID available though in the Page_PreInit event, seeing as the
control tree has not yet been built, it would be difficult for the Page
to
calculate the UniqueID, and typically the Control instance would be null
as
well no?

--
Chad Scharf
_______________ _______________ _
http://www.chadscharf.com
"Milosz Skalecki [MCAD]" wrote:

Howdy,

Why using cookie, wouldn't be easier just by using
string selectedValue = Request.Form[yourDropDown.Un iqueID]
?
--
Milosz
"Chad Scharf" wrote:

Unfortunately I believe the answer is no. Is there a reason you need
this
value before the page is initialized?
>
You could potentially inject the value into a cookie using JavaScript
using
the OnSubmit event of your form, then read that using the
HttpContext.Cur rent.Request.Co okies collection to retrieve your value
upon
post-back. I believe the HttpRequest stack has been created by then
and upon
calling the OnPreInit method of your page, has built these values
from the
request headers.
>
--
Chad Scharf
_______________ _______________ _
http://www.chadscharf.com
>
>
"Redhairs" wrote:
>
Is it possible to get DropDownList.Se lectedValue in Page_PreInit()
event
during the postback?

[Redhairs]

Yes, I use use the master page so the DropDownList was placed in the Content
control,
how to solve this problem?
Btw, waht's the difference between ClientID and UniqueID?
"Milosz Skalecki [MCAD]" <mi*****@DONTLI KESPAMwp.plwrot e in message
news:BC******** *************** ***********@mic rosoft.com...

Hi Redhairs,

I checked it and it works fine. Are you by any chance create this control
dynamically or drop down list is placed inside a tamplated control? Could
you
please pase some code?

Regards
--
Milosz
"Redhairs" wrote:

>It doesn't work and return error msg "Object reference not set to an
instance of an object"
"Milosz Skalecki [MCAD]" <mi*****@DONTLI KESPAMwp.plwrot e in message
news:EF******* *************** ************@mi crosoft.com...

Hi Chad,

The control tree is already created in PreInit event, as the aspx page
compiler puts all the declarations into FrameworkInitia lize() method
which
is
called from Page.ProcessReq uest (member of the IHttpHandler interface)
(have
a look at the content of your website's asp.net folder, especially at
compiled pages). Therefore, it's safe to run the code:
Request.Form[ddl.uniqueID]

Regards
--
Milosz
"Chad Scharf" wrote:

Yes, that would be easier. Sorry, I typically never use Request.Form
and
forgot about it.

Is the UniqueID available though in the Page_PreInit event, seeing as
the
control tree has not yet been built, it would be difficult for the
Page
to
calculate the UniqueID, and typically the Control instance would be
null
as
well no?

--
Chad Scharf
______________ _______________ __
http://www.chadscharf.com
"Milosz Skalecki [MCAD]" wrote:

Howdy,

Why using cookie, wouldn't be easier just by using
string selectedValue = Request.Form[yourDropDown.Un iqueID]
?
--
Milosz
"Chad Scharf" wrote:

Unfortunately I believe the answer is no. Is there a reason you
need
this
value before the page is initialized?

You could potentially inject the value into a cookie using
JavaScript
using
the OnSubmit event of your form, then read that using the
HttpContext.Cur rent.Request.Co okies collection to retrieve your
value
upon
post-back. I believe the HttpRequest stack has been created by
then
and upon
calling the OnPreInit method of your page, has built these values
from the
request headers.

--
Chad Scharf
_______________ _______________ _
http://www.chadscharf.com
"Redhairs" wrote:

Is it possible to get DropDownList.Se lectedValue in
Page_PreInit()
event
during the postback?

[=?Utf-8?B?TWlsb3N6IFNrYWxlY2tpIFtNQ0FEXQ==?=]

Howdy,

In this case (masterpage) you have to manually find the control as it has
not been referenced yet (but it has been instantiated in the contrnt place
holder):

string selectedValue =
Request.Form[Master.FindCont rol("placeholde rname").FindCon trol("ddlID").U niqueID];

It's quite nasty, so my question is why would you need that? The difference
bewteen UniqueID and ClientID is the first is used as "name" attribute for
input controls and it consists of ID + parents ID (simpifying) separated by a
dollar character, whilst ClientID is used as "id" attribute of all the html
elements that are generated by web controls/html controls with runat=server
separated by underscore char. For more info check this out:
http://www.shanebauer.com/Weblog/Per...d4da9b533.aspx
--
Milosz
"Redhairs" wrote:

Yes, I use use the master page so the DropDownList was placed in the Content
control,
how to solve this problem?
Btw, waht's the difference between ClientID and UniqueID?
"Milosz Skalecki [MCAD]" <mi*****@DONTLI KESPAMwp.plwrot e in message
news:BC******** *************** ***********@mic rosoft.com...

Hi Redhairs,

I checked it and it works fine. Are you by any chance create this control
dynamically or drop down list is placed inside a tamplated control? Could
you
please pase some code?

Regards
--
Milosz
"Redhairs" wrote:

It doesn't work and return error msg "Object reference not set to an
instance of an object"
"Milosz Skalecki [MCAD]" <mi*****@DONTLI KESPAMwp.plwrot e in message
news:EF******** *************** ***********@mic rosoft.com...
Hi Chad,

The control tree is already created in PreInit event, as the aspx page
compiler puts all the declarations into FrameworkInitia lize() method
which
is
called from Page.ProcessReq uest (member of the IHttpHandler interface)
(have
a look at the content of your website's asp.net folder, especially at
compiled pages). Therefore, it's safe to run the code:
Request.Form[ddl.uniqueID]

Regards
--
Milosz
"Chad Scharf" wrote:

Yes, that would be easier. Sorry, I typically never use Request.Form
and
forgot about it.

Is the UniqueID available though in the Page_PreInit event, seeing as
the
control tree has not yet been built, it would be difficult for the
Page
to
calculate the UniqueID, and typically the Control instance would be
null
as
well no?

--
Chad Scharf
_______________ _______________ _
http://www.chadscharf.com
"Milosz Skalecki [MCAD]" wrote:

Howdy,

Why using cookie, wouldn't be easier just by using
string selectedValue = Request.Form[yourDropDown.Un iqueID]
?
--
Milosz
"Chad Scharf" wrote:

Unfortunately I believe the answer is no. Is there a reason you
need
this
value before the page is initialized?
>
You could potentially inject the value into a cookie using
JavaScript
using
the OnSubmit event of your form, then read that using the
HttpContext.Cur rent.Request.Co okies collection to retrieve your
value
upon
post-back. I believe the HttpRequest stack has been created by
then
and upon
calling the OnPreInit method of your page, has built these values
from the
request headers.
>
--
Chad Scharf
_______________ _______________ _
http://www.chadscharf.com
>
>
"Redhairs" wrote:
>
Is it possible to get DropDownList.Se lectedValue in
Page_PreInit()
event
during the postback?

[Redhairs]

Thanks for your quick response.

I can find the
Master.FindCont rol("placeholde rname").FindCon trol("ddlID").U niqueID in
Page_PreInit()
but still get "Object reference not set to an instance of an object" if try
to access
Request.Form[Master.FindCont rol("placeholde rname").FindCon trol("ddlID").U niqueID];

But the ddlID.UnigueID is one of the keys of Request.Form collection.
Can't figure out why.


"Milosz Skalecki [MCAD]" <mi*****@DONTLI KESPAMwp.plwrot e in message
news:9C******** *************** ***********@mic rosoft.com...

Howdy,

In this case (masterpage) you have to manually find the control as it has
not been referenced yet (but it has been instantiated in the contrnt place
holder):

string selectedValue =
Request.Form[Master.FindCont rol("placeholde rname").FindCon trol("ddlID").U niqueID];

It's quite nasty, so my question is why would you need that? The
difference
bewteen UniqueID and ClientID is the first is used as "name" attribute for
input controls and it consists of ID + parents ID (simpifying) separated
by a
dollar character, whilst ClientID is used as "id" attribute of all the
html
elements that are generated by web controls/html controls with
runat=server
separated by underscore char. For more info check this out:
http://www.shanebauer.com/Weblog/Per...d4da9b533.aspx
--
Milosz
"Redhairs" wrote:

>Yes, I use use the master page so the DropDownList was placed in the
Content
control,
how to solve this problem?
Btw, waht's the difference between ClientID and UniqueID?
"Milosz Skalecki [MCAD]" <mi*****@DONTLI KESPAMwp.plwrot e in message
news:BC******* *************** ************@mi crosoft.com...

Hi Redhairs,

I checked it and it works fine. Are you by any chance create this
control
dynamically or drop down list is placed inside a tamplated control?
Could
you
please pase some code?

Regards
--
Milosz
"Redhairs" wrote:

It doesn't work and return error msg "Object reference not set to an
instance of an object"
"Milosz Skalecki [MCAD]" <mi*****@DONTLI KESPAMwp.plwrot e in message
news:EF******* *************** ************@mi crosoft.com...
Hi Chad,

The control tree is already created in PreInit event, as the aspx
page
compiler puts all the declarations into FrameworkInitia lize() method
which
is
called from Page.ProcessReq uest (member of the IHttpHandler
interface)
(have
a look at the content of your website's asp.net folder, especially
at
compiled pages). Therefore, it's safe to run the code:
Request.Form[ddl.uniqueID]

Regards
--
Milosz
"Chad Scharf" wrote:

Yes, that would be easier. Sorry, I typically never use
Request.Form
and
forgot about it.

Is the UniqueID available though in the Page_PreInit event, seeing
as
the
control tree has not yet been built, it would be difficult for the
Page
to
calculate the UniqueID, and typically the Control instance would be
null
as
well no?

--
Chad Scharf
______________ _______________ __
http://www.chadscharf.com
"Milosz Skalecki [MCAD]" wrote:

Howdy,

Why using cookie, wouldn't be easier just by using
string selectedValue = Request.Form[yourDropDown.Un iqueID]
?
--
Milosz
"Chad Scharf" wrote:

Unfortunately I believe the answer is no. Is there a reason you
need
this
value before the page is initialized?

You could potentially inject the value into a cookie using
JavaScript
using
the OnSubmit event of your form, then read that using the
HttpContext.Cur rent.Request.Co okies collection to retrieve your
value
upon
post-back. I believe the HttpRequest stack has been created by
then
and upon
calling the OnPreInit method of your page, has built these
values
from the
request headers.

--
Chad Scharf
_______________ _______________ _
http://www.chadscharf.com
"Redhairs" wrote:

Is it possible to get DropDownList.Se lectedValue in
Page_PreInit()
event
during the postback?