Migrating from ASP to ASP.NET

This tutorial guides you through migrating a classic ASP application to ASP.NET. ASP and ASP.NET can run side-by-side on the same IIS server, so you can migrate incrementally.

Key Differences

Step 1: Set Up the ASP.NET Project

1. Create a new ASP.NET Web Application in Visual Studio .NET.
2. Copy static files (images, CSS, JavaScript) from the ASP application.
3. Configure the connection string in web.config:

   <configuration>
     <appSettings>
       <add key="ConnectionString"
            value="Server=SQLSERVER01;Database=FlamenetDB;Integrated Security=true;" />
     </appSettings>
   </configuration>
   

Step 2: Convert Data Access

Replace ADO Recordset code with ADO.NET:

Before (ASP/ADO):

<%
Set conn = Server.CreateObject("ADODB.Connection")
conn.Open Application("ConnString")
Set rs = conn.Execute("SELECT * FROM Products WHERE Active = 1")
Do While Not rs.EOF
    Response.Write rs("ProductName") & "<br>"
    rs.MoveNext
Loop
rs.Close : conn.Close
%>

After (ASP.NET/ADO.NET):

string connStr = ConfigurationSettings.AppSettings["ConnectionString"];
using (SqlConnection conn = new SqlConnection(connStr))
{
    conn.Open();
    SqlCommand cmd = new SqlCommand(
        "SELECT ProductName FROM Products WHERE Active = 1", conn);
    using (SqlDataReader reader = cmd.ExecuteReader())
    {
        while (reader.Read())
        {
            Response.Write(reader["ProductName"] + "<br>");
        }
    }
}

Step 3: Replace COM Objects

Many COM objects used in ASP have .NET equivalents:

Migration Tips

• Migrate one page at a time — ASP and ASP.NET can run side-by-side
• Replace On Error Resume Next with proper try/catch blocks
• Use Server.HtmlEncode() (ASP.NET version) instead of manual escaping
• Move connection strings out of code into web.config
• Replace Session and Application objects carefully — ASP.NET Session is not shared with classic ASP Session