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Listbox in a div container.....how to make it work?!?!?1

Posted on 2006-10-31
16
393 Views
Last Modified: 2008-02-01
I have a listbox on my asp.net website.  I wanted to display horizontal scrollbars on the listbox...so I put the listbox in a div container.  Now the scrollbars both display, however I cannot seem to capture the selected item in the listbox now.  It selects fine but the selectedindex is always -1!!!!!!
any help is much appreciated:
here is the code for the listbox:

           <div id="myContainer" style="height:70px;width:223px;overflow:scroll; z-index: 116; left: 145px; position: absolute; top: 361px;" atomicselection="false" >
 <asp:ListBox ID="ChangeType" runat="server" DataSourceID="ChangeDataSource"
            DataTextField="NAME"
            DataValueField="NAME" SelectionMode="Multiple"></asp:ListBox>
  </div

it took me ages to get the scrollbar part to work and now this problem :-)

HELP :-)
0
Comment
Question by:ciara_barry123
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16 Comments
 
LVL 13

Expert Comment

by:jeebukarthikeyan
ID: 17841851
hi,

i have reproduced the code ur using

if(!IsPostBack)
{
  connect();//ur databing code
}

put ur list box connecting code with the if(!IsPostBack)

it works

b u d d h a
0
 

Author Comment

by:ciara_barry123
ID: 17841924
jeebukarthikeyan  - thanks for the comment :-)

excuse my ignorance...i'm a little confused as to where exactly I would put the code?

If(!IsPostBack)
{
  connect();//ur databing code
}

I'm using VB code....
0
 
LVL 13

Expert Comment

by:jeebukarthikeyan
ID: 17841984
hi,

i have created some thing like ur
<form id="Form1" method="post" runat="server">
      <div id="myContainer" style="Z-INDEX:116;LEFT:167px;OVERFLOW:scroll;WIDTH:223px;POSITION:absolute;TOP:100px;HEIGHT:70px">
            <asp:ListBox ID="lst" runat="server" SelectionMode="Multiple" AutoPostBack="True"></asp:ListBox>
      </div>
      <asp:ListBox ID="Listbox1" runat="server" SelectionMode="Multiple" AutoPostBack="True"></asp:ListBox>
</form>

this is the function which will populate listbox

void connect()
{
  DataTable dt      =      new DataTable();
  DataColumn dc      =      new DataColumn("name");

  dt.Columns.Add(dc);

  DataRow dr      ;
  dr      =      dt.NewRow();
  dr["name"]="aaa";
  dt.Rows.Add(dr);

  dr      =      dt.NewRow();
  dr["name"]="bbb";
  dt.Rows.Add(dr);

  dr      =      dt.NewRow();
  dr["name"]="bbb";
  dt.Rows.Add(dr);

  lst.DataTextField      =      "name";
  lst.DataValueField      =      "name";

  lst.DataSource      =      dt;
  lst.DataBind();

 }

//code for selected index change
private void lst_SelectedIndexChanged(object sender, System.EventArgs e)
{
      Response.Write( lst.SelectedIndex.ToString());
}

//form load
if(!IsPostBack)
{

      connect();
}

b u d d h a
0
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Author Comment

by:ciara_barry123
ID: 17842012

jeebukarthikeyan  - thanks again for the comments....
I think I was confused because I'm using vb not c#?
I'll post all of my code to see if it helps:

in the source section:
          <div id="myContainer" style="height:70px;width:223px;overflow:scroll; z-index: 116; left: 145px; position: absolute; top: 361px;" atomicselection="false" >
 <asp:ListBox ID="ChangeType" runat="server" DataSourceID="ChangeDataSource"
            DataTextField="NAME"
            DataValueField="NAME" SelectionMode="Multiple" AutoPostBack="True"></asp:ListBox>
  </div> &nbsp; &nbsp;
         
on the page_load event in the vb code (I'm connecting to a datasource):
        Me.ChangeType.DataBind()
        ChangeType.Rows = ChangeType.Items.Count

0
 

Author Comment

by:ciara_barry123
ID: 17842101
and just to clarify:
when the listbox is not in the div tag, it works perfectly.
when I put it in the div tag:
when you select anything in the listbox, the selected index is always -1, so it doesn't seem to be registering that something is selected, even though when you look on the screen, you can see it's selected.

I've been stuck on this all day.....
0
 
LVL 13

Expert Comment

by:jeebukarthikeyan
ID: 17842133
hi,
where ur calling the function for populating the listboxes....

can u put the code here

b u d d h a
0
 

Author Comment

by:ciara_barry123
ID: 17842244
Hi ,
Thanks again for spending time on this:
I'm not actually calling any function to populate..it's automatically bound to the datasource so populates automatically on load....
hope this makes sense

0
 
LVL 13

Accepted Solution

by:
jeebukarthikeyan earned 320 total points
ID: 17842257
hi,

that is where the problm i think

populate the datalist form the function

it will work

u can use my connect() function
for that

b u d d h a
0
 

Author Comment

by:ciara_barry123
ID: 17843304
no it still doesn't work I'm afraid :-(

any other suggestions?
0
 
LVL 96

Expert Comment

by:Bob Learned
ID: 17843443
What happens if you use overflow:auto?

Bob
0
 

Author Comment

by:ciara_barry123
ID: 17843513
thanks Bob...but unfortunately it still doesn't work it  I use overflow auto :-(
0
 
LVL 96

Expert Comment

by:Bob Learned
ID: 17843527
Ok, because I see overflow:scroll.  Are the values for the DropDownList unique?  Did it work before you put it in the <div>?

Bob
0
 

Author Comment

by:ciara_barry123
ID: 17843553
Hi bob,

just leaving now for the day but said i'd quickly repsond

yes it worked perfectly before I put it in the div
i only put in the div so I could have a horizontal scrollbar...and when i got that working, I could no longer select :-)
typical

if you have any other ideas, let me know and I'll try them when I get into work tomorrow

thanks for the help

0
 

Author Comment

by:ciara_barry123
ID: 17843559
ps: sorry bob, I meant that I changed it to overflow auto and it still didn't work :-)
0
 
LVL 96

Assisted Solution

by:Bob Learned
Bob Learned earned 180 total points
ID: 17843731
I did a small test:

<div style="LEFT:20px;OVERFLOW:auto;WIDTH:200px;POSITION:absolute;TOP:20px;HEIGHT:300px">
   <asp:ListBox id="ListBox1" runat="server" Width="500px" AutoPostBack="True">
      <asp:ListItem Value="This is a test of the radio broadcast system">This is a test of the radio broadcast system</asp:ListItem>
    <asp:ListItem Value="This is another long text string">This is another long text string</asp:ListItem>
    </asp:ListBox>
</div>

The SelectedIndex changed as expected.

Bob
0
 

Author Comment

by:ciara_barry123
ID: 17848369
Ok I figured it out..all it needed was  a fresh brain:
in the load section I had the following code:
            Me.ChangeType.DataBind()
            ChangeType.Rows = ChangeType.Items.Count
which meant every time the user clicked on the listbox, the form was loaded and thus the listbox was reloaded...losing the selection
i added the following code to ensure it was only databound on the first load and it works perfectly....

  If FirstTimeLoad <> False Then
                    Me.ChangeType.DataBind()
            ChangeType.Rows = ChangeType.Items.Count
            FirstTimeLoad = False
        End If
thanks for all the help I'm going to split the points:
hope you think that's fair......


 
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