为什么我的RequiredFieldValidators没有停止发布表单？

Question

Per the erroneously indicated "duplicate", no validation occurs when the button is clicked. The postback proceeds unimpeded by validation behavior. I thought I was clear on this when I said "the page is still posting" but apparently I was wrong.

This shouldn't be so confusing but I'm lost.

I've got several RequiredFieldValidator controls on my page in which I'm not specifying an InitialValue so the validators should fail to validate if the ControlToValidate 's value is empty ( according to documentation ).

The page is still posting, however, even with empty values (although Page.IsValid returns false in this case).

<div class="form-group">
    <label class="col-md-3 control-label">Registered Name</label>
    <div class="col-md-9">
        <asp:TextBox runat="server" ID="RegisteredName" CssClass="form-control" />
        <asp:RequiredFieldValidator runat="server" ID="RegisteredNameRequiredFieldValidator" ControlToValidate="RegisteredName" ErrorMessage="*" ForeColor="Red" />
    </div>
</div>

<div class="col-md-12">
    <asp:Button runat="server" ID="Save" Text="Save" CssClass="btn btn-primary" OnClick="Save_Click" CausesValidation="true" />
</div>

Here's the backend code:

protected async void Save_Click(object sender, EventArgs e)
{
    try
    {
        if (Page.IsValid)
        {
            // Save the form data to the database.
            var company = await SaveCompany();
            await SaveCompanyMeta(company);
            await SaveBankingDetails(company);
            await SaveContacts(company);
            await SaveShareholders(company);

            // Indicate that the operation processed successfully.
            var msg = $"Company details for new company {company.RegisteredName} have been saved. Redirecting to company list...";
            ShowSnackbar(msg, "/Companies");
        }
    }
    catch (Exception ex)
    {
        ShowSnackbar(ex.Message);
    }
}

Now I'm more than happy to leave this as-is considering it still prevents corrupt data from being posted to the database, but the fact that it doesn't indicate anything on the UI is what I'm having a problem with.

I've gone and built this more or less according to asp.net-tutorials.com but I'm not having any luck getting it to work correctly. Have I missed something? Why isn't this showing any errors on the page when validation fails?

Answer 1

Worked around by adding the HTML5 required attribute to the fields that I want to validate. Either on its own or along with the logic already in place, the form submission is now not happening and the UI indicates that the field is required:

<asp:TextBox runat="server" ID="RegisteredName" CssClass="form-control" required />