validate empty value on textbox ASP.NET C#

Question

I have problem about validating empty textbox

My textbox

<asp:TextBox ID="TextBox1" runat="server" MaxLength="50" Width="272px" AutoCompleteType="Disabled">

My label

<asp:Label ID="warning" runat="server" Text="you forgot about this" ForeColor="Red" Visible="false"></asp:Label>

my validation

if (TextBox1.Text == "")
            {
                warning.Visible = true;
            }

it can validate the empty textbox but it can't validate space input

can anybody help me please?

why you didn't use ASP.NET validators control?

oussama abdou
– oussama abdou

2014-10-29 12:32:15 +00:00
Commented Oct 29, 2014 at 12:32 — oussama abdou
– oussama abdou, Commented Oct 29, 2014 at 12:32

David · Accepted Answer · 2014-10-29 12:33:15Z

2

That's because a space isn't "", so they're not equal.

You can use .IsNullOrWhiteSpace instead:

if (string.IsNullOrWhiteSpace(TextBox1.Text))

This has the added benefit of also checking for null (though in this particular case I don't think .Text would ever be null) as well as any other purely whitespace characters.

answered Oct 29, 2014 at 12:33

David

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Comments

esolCrusador · Accepted Answer · 2014-10-29 12:35:25Z

0

try to use RequiredFieldValidator it validates both client side and server side and also ignore whitespaces during validation. http://msdn.microsoft.com/ru-ru/library/system.web.ui.webcontrols.requiredfieldvalidator(v=vs.110).aspx

answered Oct 29, 2014 at 12:35

esolCrusador

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