如何避免从下拉列表中选择？

Question

I don't know how to avoid select text listed when I am populating drop down at run time.

    DataRow row = ds.Tables[0].NewRow();
    row["cabTypeId"] = "0";
    row["cabType"] = "Select";
    ds.Tables[0].Rows.InsertAt(row, 0);
    ddlCabSize.DataTextField = ds.Tables[0].Columns["cabType"].ToString();
    ddlCabSize.DataValueField = ds.Tables[0].Columns["cabTypeId"].ToString();
    ddlCabSize.DataSource = ds.Tables[0];
    ddlCabSize.DataBind();

If i will select drop down list means "select" should not show to dropdownlist. Help me that how to do it?

Answer 1

For the need on insert, you can add this code bu using Add Method

ddlCabSize.DataBind();
ddlCabSize.Items.Add(new ListItem("Select .."));

link : http://msdn.microsoft.com/fr-fr/library/e7s6873c.aspx

Note : You can also use Insert Method

You must add Columns to your tables

DataColumn dc = new DataColumn ("Name", Type);
dt.Columns.Add(dc);

So :

DataColumn dc = new DataColumn ("cabType", typeof(string));

Answer 2

Use below code.

ddlCabSize.DataSource = ds.Tables[0];
ddlCabSize.DataTextField = ds.Tables[0].Columns["cabType"].ToString();
ddlCabSize.DataValueField = ds.Tables[0].Columns["cabTypeId"].ToString();
ddlCabSize.DataBind();
ddlCabSize.Items.Insert(0, new ListItem("Select Below","0"));

Answer 3

Not sure what you are asking.

Try swapping your values around.

ddlCabSize.DataTextField = ds.Tables[0].Columns["cabTypeId"].ToString();
ddlCabSize.DataValueField = ds.Tables[0].Columns["cabType"].ToString();

Answer 4

If i get your question correctly, you want t remove the item with the text "Select" or value = "0" from the dropdown list once the selection is changed

You can use jquery to do this very easily, for that you need to know the clientId of your dropdown list which is very easy to get using the ddlCabSize.ClientID property

add jquery reference to your page like this

<script src="http://code.jquery.com/jquery-1.9.1.min.js"></script>

and copy the script code

<script type="text/javascript">
 $(document).ready(function () {
     $("#<#= ddlCabSize.ClientID #>").change(function () {
         $("#<#= ddlCabSize.ClientID #> option[value='0']").remove();
     });
 });
</script>

See the fiddle for more info