asp.net 中的下拉列表值 [英] drop down list value in asp.net

问题描述

我想在无法选择的下拉列表中添加一个值，例如标题.例如:我有一个月的下拉列表.第一个项目应该是选择月份"，这不应该被选中.接下来是从一月到十二月.我该怎么做?

I want to add a value to the drop down list that cannot be selected, like a title. Ex: I have a month drop down list. The very first item should be "select month" this should not be selected. And next is from January to december. How can I do that?

这是我当前的代码.

string selectmonth = "select * from tblmonth";
SqlCommand scmselect = new SqlCommand(selectmonth, scnbuboy);

SqlDataReader sdrselect = scmselect.ExecuteReader();

drmonth.DataTextField = "month";
drmonth.DataValueField = "monthID";
drmonth.DataSource = sdrselect;

drmonth.DataBind();

推荐答案

<asp:DropDownList ID="DdlMonths" runat="server">
    <asp:ListItem Enabled="true" Text="Select Month" Value="-1"></asp:ListItem>
    <asp:ListItem Text="January" Value="1"></asp:ListItem>
    <asp:ListItem Text="February" Value="2"></asp:ListItem>
    ....
    <asp:ListItem Text="December" Value="12"></asp:ListItem>
</asp:DropDownList>

你甚至可以使用一个 RequiredFieldValidator 忽略这个项目，它认为它没有被选中.

You can even use a RequiredFieldValidator which ignore this item, it considers it as unselected.

<asp:RequiredFieldValidator ID="ReqMonth" runat="server" ControlToValidate="DdlMonths"
    InitialValue="-1">
</asp:RequiredFieldValidator>

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