Question

I got a weird problem. I use a DropDownList item in a web application. after i check for the first time one of the options all the items are added to end of the list.
initialized like this

 protected void Page_Load(object sender, EventArgs e)
    {
        string myXMLfile = Server.MapPath("~/VMlist.xml");
        DataSet dsMachines = new DataSet();
        try
        {
            dsMachines.ReadXml(myXMLfile);
            DropDownList1.DataSource = dsMachines;
            DropDownList1.DataValueField = "machineID";
            DropDownList1.DataTextField = "machineName";
            DropDownList1.DataBind();

        }
        catch (Exception ex)
        {
            Response.Write(ex.ToString());
        }
    }

and the SelectedIndexChanged:

protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
    {

        machineOS.Text = OSdata.OSDataRetrieve.getOSInfo(DropDownList1.SelectedItem.Text);

    }

i use XML initializing. I’m also adding an image of ‘before’ and ‘after’

Answer 1

You need to add the following to your Page_Load:

if (!Page.IsPostBack)
{
    //code to bind dropdown
}

Your list is being bound each time the page posts back, which is why you’re getting duplicates. Add the above line, and you should be all set.