problem with dropdownlist

Question

4.33/5 (3 votes)

See more:

SQL-Server-2005

VB

ASP.NET

, +

Hi All,

I have Table Name Account & i m binding a dropdownlist with this table
binding code is:

VB

If IsPostBack = False Then
    Dim SqlAdapter As New SqlDataAdapter("Select AccountType,Cost From Accounts Where IsAddOn=1 order by AccountType ", ConnectionString)
    Dim SqlDataset As New DataSet
    SqlAdapter.Fill(SqlDataset)
    DropDownList1.DataSource = SqlDataset.Tables(0)
    DropDownList1.DataTextField = "AccountType"
    DropDownList1.DataValueField = "Cost"
    DropDownList1.DataBind()
End If

problem is:
when I select either 5th, 8th or 9th item its shows 2nd item selected.

please suggest me where I am doing wrong

Posted 29-May-11 23:28pm

prateekfgiet

Updated 29-May-11 23:52pm

Ankur^\m/

v2

Add a Solution

Comments

hoa20101988 30-May-11 5:33am

you check dropdowm list

Ankur^\m/ 30-May-11 5:33am

How can a dropdownlist show 2 items at a time?

prateekfgiet 30-May-11 5:39am

i m not saying that i m selecting 2 or more value at time,while i m selecting 5th its shows 2nd item selected same happen with 8th and 9th item

Ankur^\m/ 30-May-11 5:55am

I have added the clarification to the question.
The code seems fine to me. I still have a doubt. When you select the 5th (or other mentioned items) does the page posts back? Or these items do not get selected at all and it always automatically changes to 2nd item without page posting back to the server?

prateekfgiet 30-May-11 6:03am

yes page goes to post back.

actually i have 2 text box where i print selected value,seleted index on selection change event.
when i select 5th(or other) text box shows 2nd item n drop down list also shows 2nd item selected

Ankur^\m/ 30-May-11 6:31am

I didn't get any notification for the comment and saw it just now.
Give the selectedindexchanged event code of the dropdown list. There must be some problem there or in the page load.

prateekfgiet 30-May-11 7:59am

well thanks dear for your help
:-)

2 solutions

Solution 1

when i select either 5th, 8th or 9th item its shows 2 item selected
Does not make any sense. It's not related to your code above, all looks ok.

Not sure, how or why multiselected items are shown, may be you have put it to allow multiselect - if so, put it off. Please debug a little or share the values at 5th, 8th, 9th position as there must be something with those value selection it is happening. It's a specific issue only with you and probably code written is responsible.

Posted 29-May-11 23:33pm

Sandeep Mewara

Comments

prateekfgiet 30-May-11 5:42am

i m saying that whn i m selecting 5th its shows 2nd item selected same happen with 8th and 9th item

Sandeep Mewara 30-May-11 5:49am

Debug it. There is something in your code. This is not a normal or expected behavior and debug should help in narrow down the issue.

Ankur^\m/ 30-May-11 5:49am

multi-select in a drop down list???

Sandeep Mewara 30-May-11 6:09am

Yep. By default, the user can only select one option.
But, using a 'MULTIPLE' attribute - user can select multiple options in a SELECT-OPTIONS html control.

Ankur^\m/ 30-May-11 6:30am

We do not have any such option in a asp dropdownlist which the user is using. Specifying multiple attribute in a select box will make it look like a asp Listbox which take more space.
I think I got the problem. The page posts back and there is something wrong in his page load event.

prateekfgiet 30-May-11 6:35am

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If IsPostBack = False Then
Dim SqlAdapter As New SqlDataAdapter("Select AccountType,Cost From Accounts Where IsAddOn=1 order by AccountType ", ConnectionString)
Dim SqlDataset As New DataSet
SqlAdapter.Fill(SqlDataset)
DropDownList1.DataSource = SqlDataset.Tables(0)
DropDownList1.DataTextField = "AccountType"
DropDownList1.DataValueField = "Cost"
DropDownList1.DataBind()
End If
End Sub

Protected Sub DropDownList1_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles DropDownList1.SelectedIndexChanged
TextBox1.Text = DropDownList1.SelectedIndex
TextBox2.Text = DropDownList1.SelectedItem.Text
TextBox3.Text = DropDownList1.SelectedValue
End Sub

Ankur^\m/ 30-May-11 6:45am

Well the code seems fine to me. That's the only code you have in both the methods?

The best option you have now is to debug the code when the page is posted back. Use the watch window to keep a watch on DropDownList1.SelectedValue.
See what's happening at every line of code that is executing.

prateekfgiet 30-May-11 6:53am

i have used watch,and same value shown there.

Sandeep Mewara 30-May-11 7:49am

Hmmm... I have not tried so difficult to say much, just read/knew from sometime that this was an attribute possible. Further, we can add it from server side to ASP.NET dropdown using attributes.Add.

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

rahkan · Accepted Answer · 2011-05-30T00:46:00

Solution 2

The item's most likely have the same value? If more than one item has the same value then asp.net will select the first item it comes to in the drop down list during postback. You need to make sure that each item in the DropDownList has a unique value. You may have to select the cost from the database during your postback event instead of using it as the DataValueField for the drop down list.

Posted 30-May-11 0:46am

rahkan

Updated 30-May-11 1:02am

v2

Comments

prateekfgiet 30-May-11 6:56am

but the problem is, drop down text & value both are different at each item

rahkan 30-May-11 7:04am

so no items in the list have the same cost? Have you tried running the select statement directly on the database to see what results you get back? Can you post those results?

prateekfgiet 30-May-11 7:06am

hv few items with same value but its not happen only with same value item.

Ankur^\m/ 30-May-11 7:08am

No what he means is - check the "Cost" column returned by the database. Does it have same value for 5th, 8th and 9th item?

prateekfgiet 30-May-11 7:14am

i got his point,
5th,8th item have same cost value but 9th have different cost value.
same problem with many other index what have different text as well as cost.

Ankur^\m/ 30-May-11 7:52am

I have no clue why I am not getting your notifications. I guess I will have to report it. :sigh:
Anyways good to see you solved it.

rahkan 30-May-11 7:11am

for testing purposes try just using the AccountType as both the DataTextField and DataValueField and see if the problem persists, well, that's if all of the AccountType items are unique, otherwise you'll probably get the same results

prateekfgiet 30-May-11 7:20am

ok i have tested what you suggest.its working fine when i used AccountType both Place at textfield and valuefield.
wht should i do for cost???
any suggestion please

rahkan 30-May-11 7:26am

You'll probably need to pull the cost for the AccountType during your postback event (SelectedIndexChanged event?).

prateekfgiet 30-May-11 7:45am

ok thanks
rahkan
:-)