DropDownList用DataSourceID绑定后，无法再手动添加项目

Question

DropDownList用DataSourceID绑定后，无法再手动添加项目
<asp:DropDownList ID="DropDownList1" runat="server" DataSourceID="SqlDataSource1" DataTextField="NAME" DataValueField="DEPTNAME"></asp:DropDownList>我想在程序再添加一个项目 DropDownList1.Items.Insert(0, new ListItem("aa"));

Answer 1

.....数据操作
                    DropDownList1.DataSource=dr;
                    DropDownList1.DataBind();
                    dr.Close();
                     if (DropDownList1.Items.Count==0)
                        {
                            DropDownList1.Items.Add(new ListItem("aa","0"));
                        }
                        else
{
                            DropDownList1.Items.Insert(0,new ListItem("aa","0"));
                        }

Answer 2

可以的，但要把 AppendDataBoundItems = True

Answer 3

绑定完后
再加一句
DropDownList1.Items.Insert(0,new ListItem("aa","0"));