Redirect to different page based on the Regular Expression using C# and VB.Net in ASP.Net

Hey chetan,

Please refer below sample.

HTML

<div>
    <asp:TextBox runat="server" ID="txtName" />
    <asp:Button Text="Check" runat="server" OnClick="Check" />
</div>

Namespaces

C#

using System.Text.RegularExpressions;

VB.Net

Imports System.Text.RegularExpressions

Code

C#

protected void Check(object sender, EventArgs e)
{
    bool isValid = true;
    bool isValid1 = true;
    Regex regex = new Regex(@"^([\w-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([\w-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$");
    string[] values = txtName.Text.Trim().Split(' ');
    for (int i = 0; i < values.Length; i++)
    {
        isValid = regex.IsMatch(values[i].Trim());
        isValid1 = !regex.IsMatch(values[i].ToString().Trim()); ;
        if (isValid)
        {
            Response.Redirect("addlisting.aspx");
            break;
        }
    }
    if (isValid1 && IsValid)
    {
        Response.Redirect("addlistingpost.aspx");
    }
}

VB.Net

Protected Sub Check(ByVal sender As Object, ByVal e As EventArgs)
    Dim isValid As Boolean = True
    Dim isValid1 As Boolean = True
    Dim regex As Regex = New Regex("^([\w-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([\w-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$")
    Dim values As String() = txtName.Text.Trim().Split(" "c)
    For i As Integer = 0 To values.Length - 1
        isValid = regex.IsMatch(values(i).Trim())
        isValid1 = Not regex.IsMatch(values(i).ToString().Trim())
        If isValid Then
            Response.Redirect("addlisting.aspx")
            Exit For
        End If
    Next
    If isValid1 AndAlso IsValid Then
        Response.Redirect("addlistingpost.aspx")
    End If
End Sub

Screenshot