Asp.net: Generate random password

In this article I am going to explain how to generate random password in asp.net using C# and VB.net.

Implementation:

HTML Markup:

  <fieldset style="width:25%">

    <legend>Generate Random Password</legend>

    <table>

    <tr><td>Enter length :</td><td><asp:TextBox ID="txtlength" runat="server"></asp:TextBox></td></tr>

    <tr><td></td><td></td></tr>

    <tr><td></td><td><asp:Button ID="btnsubmit" runat="server" Text="Generate" /></td></tr>

    <tr><td colspan="2"><asp:Label ID="lbloutput" runat="server"></asp:Label></td></tr>

    </table>       

    </fieldset>

Create a method to Generate random password

Create a method to generate the alphanumeric random password.

C# code:

protected void btnsubmit_Click(object sender, EventArgs e)

    {

        GenerateRandomPassword (Convert.ToInt32(txtlength.Text));

    }

    private void GenerateRandomPassword (int length)

    {

        try

        {

            string numbers = "0123456789";

            string LargeAplhabets = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";

            string SmallAplhabets = "abcdefghijklmnopqrstuvwxyz";

            string allowedChars = numbers + LargeAplhabets + SmallAplhabets;

            Random objrandom = new Random();

            char[] chars = new char[length];

            for (int i = 0; i < length; i++)

            {

                chars[i] = allowedChars[Convert.ToInt32((allowedChars.Length - 1) * objrandom.NextDouble())];

            }

            string otp = new string(chars);

            lbloutput.Text = otp;

        }

        catch (Exception ex)

        {

        }

    }

VB.net code

Protected Sub btnsubmit_Click(sender As Object, e As System.EventArgs) Handles btnsubmit.Click

        GenerateRandomPassword (Convert.ToInt32(txtlength.Text))

    End Sub

    Private Sub GenerateRandomPassword(length As Integer)

        Try

            Dim numbers As String = "0123456789"

            Dim LargeAplhabets As String = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"

            Dim SmallAplhabets As String = "abcdefghijklmnopqrstuvwxyz"

            Dim allowedChars As String = Convert.ToString(numbers & LargeAplhabets) & SmallAplhabets

            Dim objrandom As New Random()

            Dim chars As Char() = New Char(length - 1) {}

            For i As Integer = 0 To length - 1

                chars(i) = allowedChars(Convert.ToInt32((allowedChars.Length - 1) * objrandom.NextDouble()))

            Next

            Dim otp As New String(chars)

            lbloutput.Text = otp

        Catch ex As Exception

        End Try

    End Sub