Server-side validation in ASP.NET 2.0

Question

Hi All,

My application is in ASP.NET 2.0 with C#. I have a regular expression validator with the regular expression ^[0-9]*(\\,)?[0-9]?[0-9]?$, now my client don't want this validation at client side but on button click i.e. Server Side.

EX: I have to check the value of txtPrice textbox

Please let me know how can I put this regular expression validation on server side.

Thanks in advance.

Answer 1

Client-side validation using server-side controls based on ValidatorBase takes place only on PostBack i.e. on any server-side button/linkbutton click.

So you can use RegularExpressionValidator:

<asp:TextBox runat="server" ID="txtPrice" />
<asp:RegularExpressionValidator runat="server" ControlToValidate="txtPrice" ValidationExpression="^[0-9]*(\\,)?[0-9]?[0-9]?$" ErrorMessage="Input is incorrect" />

Also you can use CustomValidator:

<asp:TextBox runat="server" ID="txtPrice" />
<asp:CustomValidator runat="server" ControlToValidate="txtPrice" ErrorMessage="Input is incorrect" OnServerValidate="CustomValidator1_ServerValidate" />

protected void CustomValidator1_ServerValidate(object sender, ServerValidateEventArgs e)
{
    // use e.Value to validate and set e.IsValid
    // it's different depending on control to validate.
    // for custom controls you can set it using ValidationPropertyAttribute
}

Answer 2

Try to add EnableClientScript="false" to the validator.

Answer 3

The control will validate on the server side always, regardless of whether you also enable client-side validation. But you must then remember to check the value of Page.IsValid before accepting the postback...

As has already been said, you can turn off client-side validation with an attribute.

Answer 4

You can use a CustomValidator which can link to a server side event:

<asp:CustomValidator ID="CustomValidator1" runat="server" ErrorMessage="CustomValidator" OnServerValidate="CustomValidator1_Validate"></asp:CustomValidator>

Then server side you can validate input

protected void CustomValidator1_Validate (object source, ServerValidateEventArgs argss)
{}

Remember to wrap your submit button click with

if(IsValid) {}

To ensure all validators are respected