.gif)
Validate a Drop-Down List on a Form
The easiest way to make ensure that a user picks a value from a dropdown list is to add a value to the top of the list that isn't really a valid choice, but a prompt instead. Something like "select one" should do.
The validatedropdown.aspx page code Look like this
<%@ Page Language="C#"
%>
<!DOCTYPE html PUBLIC
"-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
protected void btnsubmit_Click(object
sender, System.EventArgs e)
{
lblmsg.Text = "You
selected: " +
ddvalidate.SelectedItem.Text.ToString();
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1"
runat="server">
<title>DropDownList
example: Check how to validate DropDownList control in asp.net</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:Label ID="lblmsg" runat="server" Font-Size="Large" ForeColor="Crimson"></asp:Label>
<br />
<asp:DropDownList ID="ddvalidate" runat="server">
<asp:ListItem Selected="True">Select One</asp:ListItem>
<asp:ListItem>.NET
Interview questions</asp:ListItem>
<asp:ListItem>asp.net
interview questions</asp:ListItem>
<asp:ListItem>Asp.Net
Calendar Example</asp:ListItem>
<asp:ListItem>Asp.Net
DataGrid Example</asp:ListItem>
<asp:ListItem>Asp.Net
DataList Example</asp:ListItem>
<asp:ListItem>Asp.Net
Gridview Example</asp:ListItem>
</asp:DropDownList>
<asp:RequiredFieldValidator
ID="RequiredFieldValidator1"
runat="server"
ControlToValidate="ddvalidate"
InitialValue="Select One"
ErrorMessage="Select One!"
>
</asp:RequiredFieldValidator>
<br />
<asp:Button ID="btnsubmit" runat="server" Text="Check Validate DropDownList" OnClick="btnsubmit_Click"
/>
</div>
</form>
</body>
</html>
