如果获得DropDownList选项的ID

Question

我从表中取出分类记录，然后邦定到DropDownlist，怎么获得DropDownlist选择分类的ID呢 

Answer 1

邦定时：DropDownlist.DataValueField = "id";取值：DropDownlist.SelectedValue;

Answer 2

DropDownlist.DataSource = ds;
DropDownlist.TextValueField = "name";
DropDownlist.DataValueField = "id";
DropDownlist.DataBind();

Answer 3

DropDownlist.DataSource = ds;
DropDownlist.TextValueField = "name";
DropDownlist.DataValueField = "id";
DropDownlist.DataBind();取值:
DropDownlist.SelectedValue;

Answer 4

da.Fill(ds, "category")
        ddl.DataSource = ds.Tables("category").DefaultView
        ddl.DataTextField = "CategoryName"
        ddl.DataBind() comm.Parameters.Add("@catename", OleDbType.VarChar, 200)
                comm.Parameters("@catename").Value = ddl.SelectedValue