Question

I just found out this weird behavior, is this a bug or what am I missing?

<asp:TextBox runat="server" Text="" ID="txtSomething" />
<asp:RequiredFieldValidator 
    ErrorMessage="errormessage" 
    ControlToValidate="txtSomething"
    runat="server"
    Text="(*) Required"
    SetFocusOnError="true"
    EnableClientScript="true"/>

With this simple code, validation works correctly, even if I write a string full of white spaces

But if I add the InitialValue property like this:

<asp:TextBox runat="server" Text="lol" ID="txtSomething" />
<asp:RequiredFieldValidator 
    ErrorMessage="errormessage" 
    ControlToValidate="txtSomething"
    runat="server"
    Text="(*) Required"
    SetFocusOnError="true"
    EnableClientScript="true"
    InitialValue="lol"/>

Note I added InitialValue=”lol” and Text=”lol”

Now if I delete the text lol validation is ignored

Why??

Answer 1

Look carefully at MSDN description:

Use this property to specify the initial value of the input control.

Validation fails only if the value of the associated input control
matches this InitialValue upon losing focus.

I think it speaks for itself.