using System; using System.Windows.Forms; namespace MyWindowsApplication { public partial class MainForm : Form { public MainForm() { InitializeComponent(); } private void btnSubmit_Click(object sender, EventArgs e) { MessageBox.Show($"You submitted {txtInput.Text}"); } } }This example shows how to use the Form class to create a simple Windows application that takes user input and displays a message box. The application consists of a Form with a single button and text box. When the user enters text into the box and clicks the button, a message box is displayed showing the entered text. Package Library: The Form class is part of the System.Windows.Forms namespace, which is included in the .NET Framework Class Library. Consequently, the package library for this class is the .NET Framework.