Autentifiacion de usuario y contraseña para entrar a pagina

[zeapaez]

Aqui esta, lo pondre en VB y luego en C#, esto es cuando se tiene una base de datos con usuario y contraseña

VB
<%@ Page Language="VB" %>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.SqlClient" %>
<script runat="server">
Protected Sub Button1_Click(ByVal sender As Object, _
ByVal e As System.EventArgs)
Dim conn As SqlConnection
Dim cmd As SqlCommand
Dim cmdString As String = "SELECT [Password] FROM [AccessTable] WHERE" & _
" (([Username] = @Username) AND ([Password] = @Password))"
conn = New SqlConnection("Data Source=localhost;Initial " & _
"Catalog=Northwind;Persist Security Info=True;User ID=sa")
cmd = New SqlCommand(cmdString, conn)
cmd.Parameters.Add("@Username", SqlDbType.VarChar, 50)
cmd.Parameters("@Username").Value = TextBox1.Text

cmd.Parameters.Add("@Password", SqlDbType.VarChar, 50)
cmd.Parameters("@Password").Value = TextBox2.Text
conn.Open()
Dim myReader As SqlDataReader
myReader = cmd.ExecuteReader(CommandBehavior.CloseConnection)
If myReader.Read() Then
FormsAuthentication.RedirectFromLoginPage(TextBox1 .Text, False)
Else
Response.Write("Invalid credentials")
End If
myReader.Close()
End Sub
</script>


C#
<%@ Page Language="C#"%>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.SqlClient" %>
<script runat="server">
protected void Button1_Click(object sender, EventArgs e)
{
SqlConnection conn;
SqlCommand cmd;
string cmdString = "SELECT [Password] FROM [AccessTable] WHERE" +
" (([Username] = @Username) AND ([Password] = @Password))";
conn = new SqlConnection("Data Source=localhost;Initial " +
"Catalog=Northwind;Persist Security Info=True;User ID=sa");
cmd = new SqlCommand(cmdString, conn);
cmd.Parameters.Add("@Username", SqlDbType.VarChar, 50);
cmd.Parameters["@Username"].Value = TextBox1.Text;
cmd.Parameters.Add("@Password", SqlDbType.VarChar, 50);
cmd.Parameters["@Password"].Value = TextBox2.Text;
conn.Open();
SqlDataReader myReader;
myReader = cmd.ExecuteReader(CommandBehavior.CloseConnection) ;
if (myReader.Read()) {
FormsAuthentication.RedirectFromLoginPage(TextBox1 .Text, false);
}

else {
Response.Write("Invalid credentials");
}
myReader.Close();
}
</script>