C#

public bool IsNumeric(string s)<br />
		{<br />
			try<br />
			{<br />
				Int32.Parse(s);<br />
			}<br />
			catch<br />
			{<br />
				return false;<br />
			}<br />
			return true;<br />
		}<br />

David Anton wrote:

2. You don't want to do this in a KeyPress event since that won't handle pasting code from another source.

David Anton wrote:

Standard Windows copy/paste doesn't trigger KeyPress events.
User the TextChanged event to capture pasting of text also.

Suamal wrote:

CheckRegExPattern

Suamal wrote:

using System.Text.RegularExpressions;

public static bool CheckNumeric(string strText)
{
return CheckRegExPattern(@"^[0-9]+$", strText.Trim());
}

using System.Text.RegularExpressions;<br />
public bool CheckNumeric(string strtext)<br />
{<br />
  System.Text.RegularExpressions.Regex rr = new Regex(@"^[0-9]+$");<br />
  return rr.IsMatch(strtext);             <br />
}<br />
<br />
///In Button click event<br />
MessageBox.Show(this.CheckNumeric(TextBox1.Text).ToString());