Binding dropdownlist

Asp.Net Hein

11y1.2k.NET

I want to stop binding dropdownlist again and again after postback.

For eg. I already bind 3 datas into dropdown list. After I choose one in drop down list and click one button called search , it will show the data of selected but now the drop down list is with 6 data. after click again , there are 9, 12 again and again.

Can anyone help me to stop binding dropdownlist.

Thanks a lot :-)

8 Replies

Know the answer? Post it — somebody with the same question will find it here.

Seliya Hilal11y ago
clear your dropdown just before binding it.

DropDownList1.Items.Clear();
.
.
.
.
DropDownList1.DataSource = dt;
DropDownList1.DataBind();

0
Pankaj Kumar Choudhary11y ago
hello @Soe answer provided by all author are correct after that your problem is not solving then you can send image of code snippet because this problem is not huge .
i think you are doing a very small mistake but this problem is not resloving..........
0
Upendra Pratap Shahi11y ago
Use this type

Design page-
How to remove all items from DropDownList, items clear

DropDownList: Items Clear

ID="Label1"
runat="server"
Font-Bold="true"
ForeColor="SeaGreen"
Text="asp.net controls"
>

ID="DropDownList1"
runat="server"
>
ListBox
RadioButtonList
SqlDataSource
SiteMapDataSource
RegularExpressionValidator

ID="Button1"
runat="server"
Font-Bold="true"
ForeColor="SaddleBrown"
Text="Clear DropDownList"
OnClick="Button1_Click"
/>

Codebehind Page-

protected void Button1_Click(object sender, System.EventArgs e)
{
DropDownList1.Items.Clear();
}

If this is satisfied you kindly mark the answer as Accepted Answer
0
Ravi Patel11y ago
Hi Soe,

just clear the dropdownlist item before bind

DropDownList1.Items.Clear();
// then write your binding code
0
Nilesh Jadav11y ago
Hello Soe

Well you have to add your binding code for dropdownlist in --

if (!page.IspostBack)
{
//bind your dropdown here.
}

You can code it like this -->
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
SqlConnection con = new SqlConnection(@"Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\Database.mdf;Integrated Security=True;User Instance=True");
SqlCommand cmd = new SqlCommand("select * from tbl_media", con);
SqlDataAdapter sda = new SqlDataAdapter(cmd);
DataTable dt = new DataTable();
sda.Fill(dt);
DropDownList1.DataSource = dt;
DropDownList1.DataBind();

}
}
For more information you can check out my article on -- Bind Data To DropDownList in ASP.Net C#

For more information on cascading deropdown list you can check out this. Here you exactly clear it out dropdown list as you select one dropdown. Based on one dropdown other other dropdown will change. - Cascading A DropDownList With Another DropDownList in ASP.Net
0
Upendra Pratap Shahi11y ago
Put you code in
if(!IsPostBack ){}

and then check...if add value again and again then you code wrongly bind with control.
Share your code snippet..
0
Asp.Net Hein11y ago
Cannot... also bind again and again
0
Sanjeeb Lenka11y ago
Write your dropdown bind code inside.
if (!IsPostBack)
{
// put your code here..
}
+1

Binding dropdownlist

DropDownList: Items Clear