TabView.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace SmartRender
{
    public partial class TabView : Form
    {
        public TabView()
        {
            InitializeComponent();
        }

        private void TabView_KeyDown(object sender, KeyEventArgs e)
        {
            if(e.KeyCode == Keys.Escape)
            {
                mainForm MF = (mainForm)Application.OpenForms["mainForm"];
                MF.Opacity = 100;
                Close();
            }
        }
    }
}