Overlay

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;
using System.Diagnostics;
using System.Threading;
using System.Runtime.InteropServices;

namespace MapleLegends_Overlay
{
    public partial class Overlay : Form
    {
        [DllImport("user32.dll", SetLastError = true)]
        static extern int GetWindowLong(IntPtr hWnd, int nIndex);

        [DllImport("user32.dll")]
        static extern int SetWindowLong(IntPtr hWnd, int nIndex, int dwNewLong);

        [DllImport("user32.dll")]
        static extern IntPtr SetParent(IntPtr hwc, IntPtr hwp);

        public Overlay()
        {
            InitializeComponent();
        }

        private void Overlay_Load(object sender, EventArgs e)
        {
            this.TransparencyKey = Color.Wheat;
            this.TopMost = true;

        }

        private void button1_Click(object sender, EventArgs e)
        {
            int pidint = Convert.ToInt32(textBox1.Text);
            Process p = Process.GetProcessById(pidint);
            Thread.Sleep(1000);
            p.WaitForInputIdle();
            SetParent(p.MainWindowHandle, panel1.Handle);
            int initialStyle = GetWindowLong(this.Handle, -20);
            SetWindowLong(this.Handle, -20, initialStyle | 0x80000 | 0x20);
            //Form1 frm = new Form1();
            //Size s = frm.Size;
            //this.WindowState = FormWindowState.Maximized;
            /*this.Size = new Size(1366, 768);
            this.BackColor = Color.Green;
            panel1.Size = new Size(1366, 768);
            panel2.Size = new Size(1366, 768);
            panel2.Top += 200;*/


        }
    }
}