Can't read SelectedValue from Listbox

[Mantova]

Maybe it's simple, but I can't get it to work.
I'm originally a webdeveloper, and just started to work on a C# windows
application.
I want a list, something similar to a <select><option > object, where the
displayed value is different from the real value.
I populate the list like this, where I assume that SelectedValue is
something like the <option value="ID">

while (sql.Read())
{
currentItem=thi s.List.Items.Ad d(sql["name"]);
List.SelectedIn dex=currentItem ;
List.SelectedVa lue=sql["id"];
}

Now when I select an item in the list and do something like
textbox.Text=Li st.SelectedValu e.ToString();
it gives me an error.
Debugging gives me a <undisplayabl e value> for the SelectedValue.
What am I doing wrong here?

[Thom Little]

Here is an examples drop down as generate by Visual Studio .NET 2003 ...

<form id="Form1" method="post" runat="server">
<asp:dropdownli st id="ddlA" style="Z-INDEX: 101; LEFT: 16px; POSITION:
absolute; TOP: 184px" runat="server" AutoPostBack="T rue" Width="217">
<asp:ListItem Value="Computer Industry" Selected="True" >Computer
Industry</asp:ListItem>
<asp:ListItem Value="msdn.mic rosoft.com/msdnmag/">MSDN
Magazine</asp:ListItem>
<asp:ListItem Value="www.nwfu sion.com/">NetworkWo rld</asp:ListItem>
<asp:ListItem Value="www.zdne t.com/pcmag/">PC Magazine</asp:ListItem>
<asp:ListItem Value="www.web-developer.com/">Web
Developer</asp:ListItem>
<asp:ListItem Value="www.webt echniques.com/">Web
Techniques</asp:ListItem>
<asp:ListItem Value="www.win2 000mag.com/">Windows 2000
Magazine</asp:ListItem>
<asp:ListItem Value="www.ntsy stems.com/">Windows NT
Systems</asp:ListItem>
<asp:ListItem Value="www.wire d.com/">Wired Magazine</asp:ListItem>
</asp:dropdownlis t>
</form>

--
-- Thom Little -- www.tlaNET.net -- Thom Little Associates, Ltd.
--

"Mantova" <fl******@hotma il.com> wrote in message
news:41******** *************@d reader18.news.x s4all.nl...

Maybe it's simple, but I can't get it to work.
I'm originally a webdeveloper, and just started to work on a C# windows
application.
I want a list, something similar to a <select><option > object, where the
displayed value is different from the real value.
I populate the list like this, where I assume that SelectedValue is
something like the <option value="ID">

while (sql.Read())
{
currentItem=thi s.List.Items.Ad d(sql["name"]);
List.SelectedIn dex=currentItem ;
List.SelectedVa lue=sql["id"];
}

Now when I select an item in the list and do something like
textbox.Text=Li st.SelectedValu e.ToString();
it gives me an error.
Debugging gives me a <undisplayabl e value> for the SelectedValue.
What am I doing wrong here?

[Morten Wennevik]

On Sun, 12 Sep 2004 12:33:26 +0200, Mantova <fl******@hotma il.com> wrote:

Hi Mantova,

I'm sorry, but I don't know why your code works as the documents seem to indicate you can set the value manually without a ValueMember. I also could not set the Value. It may be that a DataSource is required.

An alternate solution is to use an ArrayList as a source (also see the USState example in the documents), or a DataSet

ArrayList dataList = new ArrayList();

while(sql.Read( ))
{
dataList.Add(ne w MyObject(sql["name"], sql["id"]));
}

List.DisplayMem ber = "MyDisplay" ;
List.ValueMembe r = "MyValue";
List.DataSource = dataList;

....

public class MyObject
{
private string disp;
private int val;

public string MyDisplay
{
get{return disp;}
}
public int MyValue
{
get{return val;}
}

public MyObject(string display, int id}
{
disp = display;
val = id;
}
}

--
Happy coding!
Morten Wennevik [C# MVP]

[Mantova]

"Thom Little" <th**@tlanet.ne t> wrote in message
news:uH******** *****@TK2MSFTNG P11.phx.gbl...

Here is an examples drop down as generate by Visual Studio .NET 2003 ...

<form id="Form1" method="post" runat="server">
<asp:dropdownli st id="ddlA" style="Z-INDEX: 101; LEFT: 16px; POSITION:
absolute; TOP: 184px" runat="server" AutoPostBack="T rue" Width="217">
<asp:ListItem Value="Computer Industry" Selected="True" >Computer
Industry</asp:ListItem>
<asp:ListItem Value="msdn.mic rosoft.com/msdnmag/">MSDN
Magazine</asp:ListItem>
<asp:ListItem Value="www.nwfu sion.com/">NetworkWo rld</asp:ListItem>
<asp:ListItem Value="www.zdne t.com/pcmag/">PC Magazine</asp:ListItem>
<asp:ListItem Value="www.web-developer.com/">Web
Developer</asp:ListItem>
<asp:ListItem Value="www.webt echniques.com/">Web
Techniques</asp:ListItem>
<asp:ListItem Value="www.win2 000mag.com/">Windows 2000
Magazine</asp:ListItem>
<asp:ListItem Value="www.ntsy stems.com/">Windows NT
Systems</asp:ListItem>
<asp:ListItem Value="www.wire d.com/">Wired Magazine</asp:ListItem>
</asp:dropdownlis t>
</form>

--
-- Thom Little -- www.tlaNET.net -- Thom Little Associates, Ltd.
--

"Mantova" <fl******@hotma il.com> wrote in message
news:41******** *************@d reader18.news.x s4all.nl...

Maybe it's simple, but I can't get it to work.
I'm originally a webdeveloper, and just started to work on a C# windows
application.
I want a list, something similar to a <select><option > object, where the
displayed value is different from the real value.
I populate the list like this, where I assume that SelectedValue is
something like the <option value="ID">

while (sql.Read())
{
currentItem=thi s.List.Items.Ad d(sql["name"]);
List.SelectedIn dex=currentItem ;
List.SelectedVa lue=sql["id"];
}

Now when I select an item in the list and do something like
textbox.Text=Li st.SelectedValu e.ToString();
it gives me an error.
Debugging gives me a <undisplayabl e value> for the SelectedValue.
What am I doing wrong here?

It's a Windows application, not web application..bu t thanx anyway

[Mantova]

"Morten Wennevik" <Mo************ @hotmail.com> wrote in message
news:opsd7p48g8 klbvpo@stone...

On Sun, 12 Sep 2004 12:33:26 +0200, Mantova <fl******@hotma il.com> wrote:

Hi Mantova,

I'm sorry, but I don't know why your code works as the documents seem to indicate you can set the value manually without a ValueMember. I also could
not set the Value. It may be that a DataSource is required.
An alternate solution is to use an ArrayList as a source (also see the USState example in the documents), or a DataSet
ArrayList dataList = new ArrayList();

while(sql.Read( ))
{
dataList.Add(ne w MyObject(sql["name"], sql["id"]));
}

List.DisplayMem ber = "MyDisplay" ;
List.ValueMembe r = "MyValue";
List.DataSource = dataList;

...

public class MyObject
{
private string disp;
private int val;

public string MyDisplay
{
get{return disp;}
}
public int MyValue
{
get{return val;}
}

public MyObject(string display, int id}
{
disp = display;
val = id;
}
}

--
Happy coding!
Morten Wennevik [C# MVP]

hmmm...maybe I'll try that.
But I hoped there would be a more elegant solution, like in <select><option >

Thanx for yer help

Greets,
DIck