Still celebrating National IT Professionals Day with 3 months of free Premium Membership. Use Code ITDAY17

x
?
Solved

Populate DropDown by Clicking Button

Posted on 2008-10-21
3
Medium Priority
?
238 Views
Last Modified: 2012-05-05
Hi

I am trying to select an item in a drop down by clicking a command button but I keep on getting an error saying "Cannot have multiple items in drop down"

The drop down does not have any duplicated so I am not sure why this is happening

Code is below.... Any ideas??

thanks


      Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)            
            If Not Page.IsPostBack Then
            ddlCountry.DataSource = DataAccess.ReaderFromSP("SELECT * FROM tblCountry ORDER BY Country_Name ASC")
            ddlCountry.DataTextField = "Country_Name"
            ddlCountry.DataValueField = "Country_ID"
            
            ddlCountry.DataBind()
            End If
      End Sub

'-- button click event
      Protected Sub cmdUseThis_Click(ByVal sender As Object, ByVal e As System.EventArgs)
Dim objCountryID As Object = DataAccess.getScalarResult("SELECT City_Country_ID FROM tblCity WHERE City_ID = " & listLocInfo.SelectedValue)

            ddlCountry.Items.FindByValue(objCountryID).Selected = True
            
      End Sub
0
Comment
Question by:patelajk
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
3 Comments
 
LVL 4

Expert Comment

by:justin-clarke
ID: 22766205
You may need to use ddlCountry.Items.Clear() before each DataRead.
0
 

Author Comment

by:patelajk
ID: 22766242
tried putting this at the top like below but i get a "Object reference not set to an instance of an object" error as the drop down is cleared:
     Protected Sub cmdUseThis_Click(ByVal sender As Object, ByVal e As System.EventArgs)
ddlCountry.Items.Clear()
Dim objCountryID As Object = DataAccess.getScalarResult("SELECT City_Country_ID FROM tblCity WHERE City_ID = " & listLocInfo.SelectedValue)

            ddlCountry.Items.FindByValue(objCountryID).Selected = True
           
      End Sub

0
 
LVL 3

Accepted Solution

by:
Blackninja2007 earned 500 total points
ID: 22766302
You need to to check if the object exists before clearing it.

if not(ddlcountry is nothing) then
  ddlcountry.items.clear()
end if
0

Featured Post

VIDEO: THE CONCERTO CLOUD FOR HEALTHCARE

Modern healthcare requires a modern cloud. View this brief video to understand how the Concerto Cloud for Healthcare can help your organization.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Today is the age of broadband.  More and more people are going this route determined to experience the web and it’s multitude of services as quickly and painlessly as possible. Coupled with the move to broadband, people are experiencing the web via …
Introduction This article shows how to use the open source plupload control to upload multiple images. The images are resized on the client side before uploading and the upload is done in chunks. Background I had to provide a way for user…
This course is ideal for IT System Administrators working with VMware vSphere and its associated products in their company infrastructure. This course teaches you how to install and maintain this virtualization technology to store data, prevent vuln…
We’ve all felt that sense of false security before—locking down external access to a database or component and feeling like we’ve done all we need to do to secure company data. But that feeling is fleeting. Attacks these days can happen in many w…
Suggested Courses

670 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question