Accept Numbers Only in a Textbox Using C#

Submitted by janobe on Tuesday, May 28, 2019 - 21:07.
In this tutorial, I’m going to teach you how to accept numbers only in a textbox using C#. This method has the capability of identifying the number only inside the textbox, this can be used in any fields that only numbers are valid, for instance, fields like Contacts, age and etc.. You will see how simple it is once you follow the instructions below.

Creating Application

Step 1

Open Microsoft Visual Studio 2015 and create a new windows form application for c#. ps1

Step 2

Do the form just like shown below. ps2

Step 3

Press F7 to open the code editor. In the code editor, create a method to set the pattern that accept numbers only.
  1.    
  2.  private static Regex NumbersOnly()
  3.         {
  4.             string StringAndNumber_Pattern = "^[0-9]*$";
  5.  
  6.             return new Regex(StringAndNumber_Pattern, RegexOptions.IgnoreCase);
  7.         }

Step 4

Instantiate the method that you have created.
  1.    
  2.         static Regex Valid_Contact = NumbersOnly();

Step 5

Double click the button and write the following codes to validate a textbox that accept numbers only when the button is clicked.
  1.    
  2.             if (Valid_Contact.IsMatch(textBox1.Text) != true)
  3.             {
  4.                 MessageBox.Show("Accept numbers only.", "Invalid", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
  5.                 textBox1.Focus();
  6.                 return;
  7.             }
  8.             else
  9.             {
  10.                 MessageBox.Show("The input data are numbers");
  11.             }
  12.  
The complete sourcecode is included. You can download it and run it on your computer. For any questions about this article. You can contact me @ Email – [email protected] Mobile No. – 09305235027 – TNT Or feel free to comment below.
Tags
numbers only in c#
Regex in C#
c#

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