add "None " to databound dropdown list

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Hi,

I have a dropdownlist that is bound to data in the code behind.
i want the default to be -- None -- at the top of the list.
if the user select the top of list i.e --None-- it should prompt as pl z select from the list ,
if user select the other than --None-- then it should continue the process

i have added the top list as

drop down.Items.Insert(0, new ListItem("-- None--", ""))

how to validate

thanks in advance

Posted 6-Mar-12 4:30am

pradeep manne

Updated 6-Mar-12 5:07am

Not Active

v5

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Comments

[no name] 6-Mar-12 10:32am

Is it a Web Project or a windows Project?

Please tag the question with proper areas.

pradeep manne 6-Mar-12 10:34am

hi,
its a web project

4 solutions

Solution 4

C#

dropdownlist1.Items.Insert(0, new ListItem("None", "0"));

for validating you can use javascript for example

C#

try
{
  if(dropdownlist1.SelectedValue == "0")
  {
     throw new Exception("<script language="javascript">" + "alert('Please select something');" + "");
  }
}

catch (Exception ex)
{
   label1.Text = ex.Message;
}</script>

Posted 6-Mar-12 18:38pm

erogaki

Solution 5

C#

function validateDropDown(){
       if(document.getElementById(<%=ddl.ClientID%>).value=='0')
       {
           alert('please select valid item.');
           return false;
       }
   }

Posted 6-Mar-12 19:18pm

Sudip Saha

Solution 1

Set the AppendDataBoundItems property in the markup and add an ListItem. Add a RangeValidator and have it validate the DropDownList. If the value for the ListItem added in the markup is -1, for instance, then you would set the MinValue for the RangeValidator to 0.

Posted 6-Mar-12 5:07am

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rajendra pratap singh · Accepted Answer · 2012-03-06T18:14:00

Solution 3

use this one.

C#

drop down.Items.Insert(0, new ListItem("-- None--", "-- None--"));

Posted 6-Mar-12 18:14pm

rajendra pratap singh

Updated 6-Mar-12 18:23pm

v2