DropDownList控件的使用方法

1. 使用代码添加数据

        <asp:DropDownList ID="DropDownList1" runat="server">
        </asp:DropDownList>

//1.1使用代码添加数据
        ListItem item = new ListItem(".net","");
        this.DropDownList1.Items.Add(item);
        item = new ListItem("java", "");
        this.DropDownList1.Items.Add(item);
        item = new ListItem("php", "");
        this.DropDownList1.Items.Add(item);
        item = new ListItem("选择全部", "");
        this.DropDownList1.Items.Insert(, item);//在第一个索引处添加‘选择全部’选项

2. 使用代码绑定数据源

        <asp:DropDownList ID="DropDownList2" runat="server">
        </asp:DropDownList>

//2.1使用代码绑定数据源
        CategoriesManager manager = new CategoriesManager();
        this.DropDownList2.DataSource=manager.GetDataTable();
        this.DropDownList2.DataTextField = "name";
        this.DropDownList2.DataValueField = "id";
        this.DropDownList2.DataBind();
        this.DropDownList2.Items.Insert(,new ListItem("选择全部", ""));

3. 使用数据绑定控件绑定数据源

        <asp:DropDownList ID="DropDownList3" runat="server"
            DataSourceID="SqlDataSource1" DataTextField="Name" DataValueField="Id">
        </asp:DropDownList>
        <asp:SqlDataSource ID="SqlDataSource1" runat="server"
            ConnectionString="<%$ ConnectionStrings:BookShopConnectionString %>"
            SelectCommand="SELECT [Id], [Name] FROM [Categories]"></asp:SqlDataSource>