Comparing date with exceptional date in asp.net Validator - html

Question

I am using compare validator of asp.net to compare the Date, I am comparing input date with today's date for that I have written code as below.
<asp:CompareValidator ID="StartDateCompareVal" ValidationGroup="vgStep4" runat="server"
ControlToValidate="txtDueDate" Display="Dynamic" ErrorMessage="Dateshould be greater than today's date."
Operator="GreaterThan" ValueToCompare="<%# DateTime.Today.ToShortDateString() %>"
Type="Date"></asp:CompareValidator>
It is working fine, but Now my requirement is that if someone enters date as 00/00/0000 so, No need to compare the value and should be accepted

Answer 1

Looks like you might want to use a CustomValidator instead of the CompareValidator.
.aspx page:
<form id="frmAspnet" runat="server">
<asp:ValidationSummary runat="server" ID="vSummary" />
<div>
<label>
Enter Date Greater Than Today:
<asp:TextBox runat="server" ID="txtDate" />
</label>
</div>
<div>
<asp:Button runat="server" ID="cmdSubmit" Text="Submit" />
</div>
</form>
code behind:
private void cmdSubmit_Click(object sender, EventArgs e)
{
String validationGroup = "vgStep4";
vSummary.ValidationGroup = validationGroup;
Page.Validate(validationGroup);
DateTime dateEntered = DateTime.TryParse(txtDate.Text, out dateEntered) ? dateEntered : DateTime.MinValue;
Page.Validators.Add(new CustomValidator()
{
IsValid = (dateEntered > DateTime.Now.Date) || (txtDate.Text == "00/00/0000"),
ValidationGroup = validationGroup,
ErrorMessage = "Date should be greater than today's date."
});
if (Page.IsValid)
{
// Date entered is valid!
// or 00/00/0000 was entered
}
}