(开发篇) 控件研究~ 下拉列表中添加一条默认的选项 "请选择"

界面上的内容

        <asp:DropDownList ID="company" runat="server" AppendDataBoundItems=true>
            <asp:ListItem Selected="true">-请选择-</asp:ListItem>
        </asp:DropDownList>

后台代码

        for (int i = company.Items.Count - 1; i > 0; i--)
        {
            company.Items.RemoveAt(i);
        }
        this.company.DataSource = ds_company;
        this.company.DataValueField = "department_no";
        this.company.DataTextField = "department_name";
        this.company.DataBind();

解析:

　　1.下拉列表中要添加 AppendDataBoundItems=true 属性

 

或者：　

            this.company.DataSource = ds_company;
            this.company.DataValueField = "department_no";
            this.company.DataTextField = "department_name";
            this.company.DataBind();

            this.company.Items.Add(new ListItem("请选择", "000000000"));
            this.company.SelectedValue = "000000000";