How to get Handle.ToInt32 () in ASP.NET Web Application

I am trying to learn and use the SDK for a vendor product. Unfortunately the documentation is sketchy and I ran into a void in my own .Net Framework knowledge.

I have working code for a Windows Forms Application and I am trying to get it to work in an ASP.NET Web Forms Application. The vendor's documentation implies that you can do this, but perhaps you cannot ..

Snapshot from the working window:

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using TRIMSDK;

private void ConnectUserBtn_Click(object sender, System.EventArgs e)
{
Database db = new Database();
Databases dbChooser = new Databases();
IDatabase dbI = dbChooser.ChooseOneUI(Handle.ToInt32());
if (dbI == null)
{
    return;
}
db.Id = dbI.Id;

      

        
        
        
      

    

Now, here's my attempt inside a click event handler for the .ASPX page:

using System;
using System.Collections.Generic;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using TRIMSDK;

protected void ConnectUserBtn_Click(object sender, EventArgs e)
{
    Database db = new Database();
    Databases dbChooser = new Databases();
    IDatabase dbI = dbChooser.ChooseOneUI(Handle.ToInt32());
    if (dbI == null)
    {
        return;
    }

      

        
        
        
      

    

I get a compilation complaint on the line just above that says "The name 'Handle' does not exist in the current context.

This part of the SDK I'm trying to use displays various modal dialogs that reflect the properties of the product in order to facilitate "client" development. I am afraid that it can only be "Windows clients" and that ASP.NET web applications cannot do this.

Is there something I can add to solve this problem?