Problems with DropDownList

[Guest]

I've been experiencing problems with getting the selected value from a DropDownList. I'm using a codebehind-solution and I'm filling a DropDownList with ListItems in the Page_Load method and all works fine. The problem arises when I try to get the selected item in the DropDownList in an event handler method mapped to a button. When I execute the following line
dropDownList.SelectedValu
I always get the value from the first ListItem
The funny thing is that I've got no problems with getting the entered text in for example a text box
What have I missed

The first line of the aspx-page looks like this
<%@ Page language="c#" Codebehind="supportsession.aspx.cs" AutoEventWireup="false" Inherits="Support_Ver2.supportsession" %

and I'm not using AutoPostBack in the DropDownList control.

 

[Martin Dechev]

Hi, Michael Strid,

Are you sure you are not setting the SelectedIndex (or SelectedItem or
SelectedValue) on every Page_Load? Can you post a short example that
illustrates the problem?

Greetings
Martin

I've been experiencing problems with getting the selected value from a

DropDownList. I'm using a codebehind-solution and I'm filling a DropDownList
with ListItems in the Page_Load method and all works fine. The problem
arises when I try to get the selected item in the DropDownList in an event
handler method mapped to a button. When I execute the following line

dropDownList.SelectedValue
I always get the value from the first ListItem.
The funny thing is that I've got no problems with getting the entered text in for example a text box.
What have I missed?

The first line of the aspx-page looks like this:
<%@ Page language="c#" Codebehind="supportsession.aspx.cs"

AutoEventWireup="false" Inherits="Support_Ver2.supportsession" %>

 

[hb]

I've been experiencing problems with getting the selected value from a

DropDownList. I'm using a codebehind-solution and I'm filling a DropDownList
with ListItems in the Page_Load method and all works fine. The problem
arises when I try to get the selected item in the DropDownList in an event
handler method mapped to a button. When I execute the following line

dropDownList.SelectedValue
I always get the value from the first ListItem.
The funny thing is that I've got no problems with getting the entered text in for example a text box.
What have I missed?

The first line of the aspx-page looks like this:
<%@ Page language="c#" Codebehind="supportsession.aspx.cs"

AutoEventWireup="false" Inherits="Support_Ver2.supportsession" %>

and I'm not using AutoPostBack in the DropDownList control.

One common mistake would be to add the ListItems every time the page loads.
You should place that code inside an "if ( !Page.IsPostBack ) { }" block, so
the Items are added once the first time the page loads, and the viewstate
should take care of any postbacks.

 

[john.winsor]

I have nearly the identical problem.

Putting the list fill in !postback does take care of propogating the last choice, but for some reason setting the selectedvalue does not have an effect, though it throws no error either.

Setting the selected value to "offices" has no effect. The dropdown defaults to none selected every time.

Ideas? Code below...

Hashtable SearchDomains = new Hashtable(3);
SearchDomains.Add("Personnel","personnel");
SearchDomains.Add("Offices","offices");
SearchDomains.Add("Units","units");

SearchDomain.DataSource = SearchDomains;
SearchDomain.DataTextField = "Key";
SearchDomain.DataValueField = "Value";
try
{
SearchDomain.SelectedValue = "offices";
}
catch (Exception ex)
{
SearchDomain.SelectedValue = null;
}
SearchDomain.DataBind();

 

[Bruno Sirianni]

try this :

Hashtable SearchDomains = new Hashtable(3);
SearchDomains.Add("Personnel","personnel");
SearchDomains.Add("Offices","offices");
SearchDomains.Add("Units","units");

SearchDomain.DataSource = SearchDomains;
SearchDomain.DataTextField = "Key";
SearchDomain.DataValueField = "Value";

SearchDomain.DataBind(); //first bind

try
{
SearchDomain.SelectedValue = "offices"; //then select the value!
}
catch
{
SearchDomain.SelectedValue = null;
}

I have nearly the identical problem.

Putting the list fill in !postback does take care of propogating the last

choice, but for some reason setting the selectedvalue does not have an
effect, though it throws no error either.

Setting the selected value to "offices" has no effect. The dropdown

defaults to none selected every time.

Ideas? Code below...

Hashtable SearchDomains = new Hashtable(3);
SearchDomains.Add("Personnel","personnel");
SearchDomains.Add("Offices","offices");
SearchDomains.Add("Units","units");

SearchDomain.DataSource = SearchDomains;
SearchDomain.DataTextField = "Key";
SearchDomain.DataValueField = "Value";
try
{
SearchDomain.SelectedValue = "offices";
}
catch (Exception ex)
{
SearchDomain.SelectedValue = null;
}
SearchDomain.DataBind();

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