BulkStockBll bll = new BulkStockBll();
DataSet ds = bll.GetBulkStock();
this.ddl_BulkStock.DataTextField = "N
ame" ;
this.ddl_BulkStock.DataVal
UEFIeld = "ID" ;
this.ddl_BulkStock.DataSource = ds;
this.ddl_BulkStock.DataBind();
this.ddl_BulkStock.
ITems.Add(new ListItem( "全部", "0" ));//第一次选择！
this.ddl_BulkStock.Items.FindByValue("0" ).Selected = true;
*******************************
this.ddl_BulkStock.Items.FindByValue(infobulkstockid).Selected = true;//第二次选择！
******************************
不要用dropDownList.Items[x].Selected = true/false，推荐用dropDownList.SelectedIndex = x。
this .ddl_BulkStock.SelectedIndex = ddl_BulkStock.Items.IndexOf(ddl_BulkStock.Items.FindByValue(infobulkstockid));
<asp:DropDownList ID="Com_Ygrenshu" runat="server" style="m
argin-left:8px;">
<asp:ListItem Value="0">请选择人数</asp:ListItem>
<asp:ListItem Selected="True" Value="5">5人以下</asp:ListItem>
<asp:ListItem Value="10">5-10 人</asp:ListItem>
<asp:ListItem Value="50">11-50 人</asp:ListItem>
</asp:DropDownList>
for (int i = 0; i < this
.COM_Ygrenshu.Items.Count;
i++)
{
Com_Ygrenshu.Items[i].Selected = false;
//如果没有上面这一句那么将出错误:不能在 DropDownList 中选择多个项
if (Com_Ygrenshu.Items[i].Value.Trim()
== ds.Tables[0].Rows[0]["Empl_Num"].ToString().Trim())
{
Com_Ygrenshu.Items[i].Selected = true;
}
}