如何从下拉列表中获取新的SelectedValue？

Question

I have a SelectedIndexChanged event on my dropdownlist. Below you can see I'm trying to set a variable as the SelectedValue. But it's giving me the SelectedValue of the old selected item rather than the new one. How do I acheive getting the new one?

protected void ddlAwesome_SelectedIndexChange(object sender, EventArgs e)
{
     int ID = Convert.ToInt32(ddlAwesome.SelectedValue);
}

Thanks

Answer 1

I think the problem is that it gives you the default value or the first one.

You must read this article : http://www.codeproject.com/Articles/776840/Why-DropDownList-SelectedValue-Does-Not-Work-Insid . The main problem is that you need a binding.

    private void BindDropDownList()
{
    // Declare a Dictionary to hold all the Options with Value and Text.
    Dictionary<string, string> options = new Dictionary<string, string>();
    options.Add("-1", "Select Option");
    options.Add("1", "Option 1");
    options.Add("2", "Option 2");
    options.Add("3", "Option 3");
    options.Add("4", "Option 4");
    options.Add("5", "Option 5");

    // Bind the Dictionary to the DropDownList.
    ddlDropDownId.DataSource = options;
    ddlDropDownId.DataTextField = "value";
    ddlDropDownId.DataValueField = "key";
    ddlDropDownId.DataBind();
}

And on page load you must bind.

   if (!IsPostBack)
    {
        BindDropDownList();
    }