user3107976 user3107976 - 1 month ago 6
ASP.NET (C#) Question

How to add a default "Select" option to this ASP.NET DropDownList control?

I am a new ASP.NET developer and I am trying to learn Linq-To-Entities. I am trying to bind a DropDownList with the Linq statement for retrieving the list of status in the Status Entity. Everything is working fine. However, I am trying now to add "Select" option to the DropDownList but It doesn't work with me.
Could you please tell me how to fix this?

ASP.NET Code:

<asp:DropDownList ID="DropDownList1" runat="server" AutoPostBack="True"
OnSelectedIndexChanged="DropDownList1_SelectedIndexChanged">


Code-Behind:

protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
DropDownList1.Items.Add(new ListItem("Select", "0", true));
bindStatusDropDownList();
}
}

private void bindStatusDropDownList()
{
Status status = new Status();
DropDownList1.DataSource = status.getData();
DropDownList1.DataValueField = "ID";
DropDownList1.DataTextField = "Description";
DropDownList1.DataBind();
}


UPDATE:

I also tried to do in the markup set of the DropDownList but it did not work too with me

<asp:DropDownList ID="DropDownList1" runat="server" AutoPostBack="True"
OnSelectedIndexChanged="DropDownList1_SelectedIndexChanged">
<asp:ListItem Selected="True" Value="0" Text="Select"></asp:ListItem>
</asp:DropDownList>

Answer

The reason it is not working is because you are adding an item to the list and then overriding the whole list with a new DataSource which will clear and re-populate your list, losing the first manually added item.

So, you need to do this in reverse like this:

Status status = new Status();
DropDownList1.DataSource = status.getData();
DropDownList1.DataValueField = "ID";
DropDownList1.DataTextField = "Description";
DropDownList1.DataBind();

// Then add your first item
DropDownList1.Items.Insert(0, "Select");
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