Databind ASP.NET List of ListItem to DropDownList issue

Farinha picture Farinha · Aug 12, 2009 · Viewed 77k times · Source

I've just come across this bizarre thing that I was expecting to work in a different (logical) way, but it doesn't. Is it a bug or a "feature"?

So there's a DropDownList that I'm populating in the codebehind with a List of ListItem. Each new ListItem gets 2 arguments that, according to the intellisense-provided documentation, correspond to its text and value:

List<ListItem> users = new List<ListItem>();
foreach (SubscriptionUser su in subscriptionDetails.UserList)
{
    users.Add(new ListItem(su.FirstName + " " + su.LastName, su.EmailAddress));
}
ddlPrimaryContact.DataSource = users;
ddlPrimaryContact.DataBind();

Now, can someone explain me why the databound DropDownList both the Text and Value set to exactly the same (the ListItem text) instead of using ListItem.Text as the Text and ListItem.Value as the Value?

ARGH!! http://www.freeimagehosting.net/uploads/fe65d0e7d5.jpg

Or am I doing something wrong?

Answer

Matthew Dresser picture Matthew Dresser · Aug 12, 2009

Hi when databinding (to anything) you need to set the DataTextField and DataValueField of your DropDownList. In your case you should use the following code

List<ListItem> users = new List<ListItem>();
foreach (SubscriptionUser su in subscriptionDetails.UserList)
{
    users.Add(new ListItem(su.FirstName + " " + su.LastName, su.EmailAddress));
}
ddlPrimaryContact.DataTextField = "Text";
ddlPrimaryContact.DataValueField = "Value";
ddlPrimaryContact.DataSource = users;
ddlPrimaryContact.DataBind();