Listbox in asp.net not getting selected items

Question

I have multiple dropdown & listbox in my webpage.

I am trying to get a list of CategoryID from a lstCatID listbox i am able to populate

Answer 1

Try to add Page.IsPostback on your Page_Load like

protected void Page_Load(object sender, EventArgs e)
{
    // Do your API code here unless you want it to occur only the first
    // time the page loads, in which case put it in the IF statement below.
    if (!Page.IsPostBack)
    {

    }
}

Code:

protected void Button1_Click(object sender, EventArgs e)
{
    string CatID = string.Empty;
    foreach (ListItem li in lstCatID.Items)
    {
        if (li.Selected )
        {
           // TODO: Whatever you are doing with a selected item.
        }
    }
    Response.Write(CatID);
}

Once i was facing the same problem and i made Postback mistake.

Hope it works.