Finding First line in the text using regular expressions with .net
In this regular expressions, we are going to find first line in the text.
Regular Expression Pattern
\A.*
A description of the regular expression:
Beginning of string
Any character, any number of repetitions
How It Works
This regular expression will check for Beginning of line followed by Any character.
ASP.NET
<%@ Page Language="VB" AutoEventWireup="false" CodeFile="Default.aspx.vb" Inherits="_Default" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Finding First line in the text using regular expressions with .net</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<span>Valid Format: enter some characters</span><br />
<asp:TextBox id="txtInput" runat="server"></asp:TextBox><br />
<asp:RegularExpressionValidator Id="vldRejex" RunAt="server" ControlToValidate="txtInput" ErrorMessage="not the begining of line" ValidationExpression="\A.*">
</asp:RegularExpressionValidator><br />
<asp:Button Id="btnSubmit" RunAt="server" CausesValidation="True" Text="Submit"></asp:Button>
</div>
</form>
</body>
</html>
C#.NET
//use System.Text.RegularExpressions befour using this function
public bool vldRegex(string strInput)
{
//create Regular Expression Match pattern object
Regex myRegex = new Regex(@"\A.*");
//boolean variable to hold the status
bool isValid = false;
if (string.IsNullOrEmpty(strInput))
{
isValid = false;
}
else
{
isValid = myRegex.IsMatch(strInput);
}
//return the results
return isValid;
}
VB.NET
‘Imports System.Text.RegularExpressions befour using this function
Public Function vldRegex(ByVal strInput As String) As Boolean
‘create Regular Expression Match pattern object
Dim myRegex As New Regex("\A.*")
‘boolean variable to hold the status
Dim isValid As Boolean = False
If strInput = "" Then
isValid = False
Else
isValid = myRegex.IsMatch(strInput)
End If
‘return the results
Return isValid
End Function
your post helped me a lot, for some reasons I thought I need \Z at the end, in fact it works simply with \A.*