How to create a mask for account Number C#

Question

I try to create a mask for a account number, for example:

That I've a function receive an String (11112222334444444444) and I would like to convert to 1111-2222-33-4444444444

applyFormatcccc function string (string cccc)
{
   1. myNum string = string.Format ("# # # # - # # # # - # # - # # # # # # # # # #", cccc);
   2. MyNum return;
}

but, it's impossible to convert because i put an String (cccc) in the first Line (1). other case was:

double num = 11112222334444444444;
worth num.ToString string = ("# # # # - # # # # - # # - # # # # # # # # # #", num)

it's the result: 11112222334444400000 -> only accept 8 bytes

How is the best form to use Apply this mask without an loops (for, while) .. as far as possible

Answer 1

Try to use Ajax markededitor extender for this.

eg :

< asp:TextBox ID = "TextBox1" runat = "server" ForeColor = "HotPink" >

< cc1:MaskedEditExtender ID = "MaskedEditExtender1" runat = "server" TargetControlID = "TextBox1" Mask = "9999-9999-99-9999999999" MaskType = "Number" MessageValidatorTip = "true" >