Dropdownlist selected value at Selectedindexchange

问题:

I'm working on asp.net website with Vb.net and I have a dropdownlist with autopostback = true and I need to get the selected value when I change the item or I want to get the item which fires the selectedindexchanged event ..

any help please..

回答1:

In ie. your Page_Load set

this.ComboBox1.SelectedIndexChanged += new System.EventHandler(ComboBox1_SelectedIndexChanged);

Then write the event handler like this:

private void ComboBox1_SelectedIndexChanged(object sender, System.EventArgs e)
{
  ComboBox comboBox = (ComboBox) sender;
  string selected = (string) comboBox.SelectedItem;
}

Make sure that in your Page_Load you write this before setting the combobox default value or you will end up with this always being the selected item:

if (Page.IsPostBack)
  return;

回答2:

try this:

    protected void list_SelectedIndexChanged(object sender, EventArgs e)
    {
        DropDownList list = (DropDownList)sender;
        string value = (string)list.SelectedValue;
    }

回答3:

If item is a Dictionary:

string value = ((KeyValuePair<string, string>)combobox.SelectedItem).Key;