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c#+ textbox values validation

• • Reply

  8 months ago

  by FRED596

  Brian Richardson

  , Australia

  Joined 11 months ago

  hi friends ,
  how can i validate the values entered in textbox in a windows form. i want the validation code for  phone number, text dateand time and email address, please give the answer clearly because i m  new to c#.
  
  thanks in advance
  Radhika
  

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• • Reply

  8 months ago

  by MZee

  Mukhtiar Zamin

  , United States

  Joined 11 months ago

  hi radhikabista,
  You can easily validate the values entered in textbox in a windows form  using Regualr Expressions (Regex). Just checkout the given regex code for your requirements.

  1. Regex for Date:- (?<Month>\d{1,2})/(?<Day>\d{1,2})/(?<Year>(?:\d{4}|\d{2}))
  2. Regex for Telephone Number:- \((?<AreaCode>\d{3})\)\s*(?<Number>\d{3}(?:-|\s*)\d{4})
  3. Regex for Email ID:- ([a-zA-Z0-9_\-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([a-zA-Z0-9\-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})
     
     Replace Regex Equation in the given code for to validate against it.
     
     private void textBox1_Validating(object sender, CancelEventArgs e)
     {
         Regex regex = new Regex("(?<Month>\d{1,2})/(?<Day>\d{1,2})/(?<Year>(?:\d{4}|\d{2}))");
         if (regex.IsMatch(textBox1.Text))
         {
             errorProvider1.SetError(textBox1, String.Empty);
         }
         else
         {
             errorProvider1.SetError(textBox1,
                   "This is not valid date");
         }
     }
     
     Hope this will help you.
     Thanks & Regards
     Dilipv
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• • Reply

  8 months ago

  by FRED596

  Brian Richardson

  , Australia

  Joined 11 months ago

  thanks dilip for yur reply,

  but i dont know anything about regix expression and how to use it. i tried to use the code as yur example but during compilation it says unexpected symbol. do i need to include some library. how and where to write the validation codes.

   

  private void text_customer_email_Validating(object sender, CancelEventArgs e)
  {
      Regex regex = new Regex("([a-zA-Z0-9_\-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([a-zA-Z0-9\-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})");
      if (regex.IsMatch(text_customer_email.Text))
      {
          errorProvider1.SetError(text_customer_email, String.Empty);
      }
      else
      {
          errorProvider1.SetError(text_customer_email,
                "This is not valid email");
      }
  }
         
  
  Regards

  Radhika 

   

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• • Reply

  8 months ago

  by MZee

  Mukhtiar Zamin

  , United States

  Joined 11 months ago

  hi radhikabista,
  For regular expressions you need to include following package.
  
  using System.Text.RegularExpressions;
  
  [quote user="radhikabista"]Regex regex = new Regex("([a-zA-Z0-9-.]+)@(([[0-9]{1,3}.[0-9]{1,3}.[0-9]{1,3}.)|(([a-zA-Z0-9-]+.)+))([a-zA-Z]{2,4}|[0-9]{1,3})");
  [/quote]

  Sorry Radhika, it's my fault. Since code is in c#  but Regex is for VB. Just change your code in quote as follows. You need to put '@' sign at the start of the Regex expression. Due to '@' sign it will become compatible for c# also.
  
  Regex regex = new Regex(@"([a-zA-Z0-9-.]+)@(([[0-9]{1,3}.[0-9]{1,3}.[0-9]{1,3}.)|(([a-zA-Z0-9-]+.)+))([a-zA-Z]{2,4}|[0-9]{1,3})");

  A regular expression (regex or regexp for short) is a special text string for describing a search pattern. You can think of regular expressions as wildcards on steroids. You are probably familiar with wildcard notations such as *.txt to find all text files in a file manager.
  For detailed study OR software to download, just checkout the given link. It contains set of Regex pattern for search strings.
  
  http://www.ultrapico.com/Expresso.htm 
  
  Hope it will help you.
  Thanks & Regards
  Dilipv
  
  
  
  
  

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• • Reply

  8 months ago

  by FRED596

  Brian Richardson

  , Australia

  Joined 11 months ago

  thanks very much for yur kind reply.

  i tried adding @  but still it says

  "the name error provider1 does not exists in current context ".

  now i have installed Expresso. i m able to generate the expressions but i couldnot save the expression to library. and i have no idea hoe to use these expression libraries to  C#.code.

  i tried 

  using System.Text.RegularExpressions;

  private void text_customer_phone_Validating(object sender, EventArgs e)
   {
  
  
            Regex regex = new Regex(@"\{9,13}");
      if (regex.IsMatch(text_customer_phone.Text))
      {
          errorProvider1.SetError(text_customer_phone, String.Empty);
      }
      else
      {
          errorProvider1.SetError(text_customer_phone,
                "This is not valid phone number.");
      }
      if (regex.IsMatch(text_customer_phone.Text))
      {
          errorProvider1.SetError(text_customer_phone, String.Empty);
      }
      else
      {
          errorProvider1.SetError(text_customer_phone,
                "This is not valid phone");
      }
          }
  

  Regards

  Radhika 

   

   

   

   

   

   

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• • Reply

  2 months ago

  by boris carloff

  mr boris carloff

  , United Kingdom

  Joined 6 months ago

  hmm!

  u need to add a component name 'errorProvider' from component tab. and athe component tab found in toolbox.

  You may need to call the " text_customer_phone_Validating(object sender, EventArgs e) " as

  text_customer_phone_Validating(null, null) from action point.

  The result is if the format match with textbox then no blink else a redExclamation icon blink beside the textbox.

  you may need to apply ur logic to get result what u want..

  B/C

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