using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;

namespace test
{
    public partial class Form1 : Form
    {

        [DllImport("dwmapi.dll")]
        private static extern int DwmIsCompositionEnabled(out bool enabled);

        [DllImport("dwmapi.dll", PreserveSig = true)]
        static extern int DwmExtendFrameIntoClientArea(IntPtr hwnd, ref MARGINS margins);

        [StructLayout(LayoutKind.Sequential)]
        public struct MARGINS
        {
            public int leftWidth;
            public int rightWidth;
            public int topHeight;
            public int bottomHeight;
        }

        public Form1()
        {
            InitializeComponent();

            BackColor = Color.Black;

            bool DwmEnabled = false;
            DwmIsCompositionEnabled(out DwmEnabled);
            if (DwmEnabled == true)
            {
                MARGINS margin;
                margin.leftWidth = -1;
                margin.rightWidth = 0;
                margin.topHeight = 0;
                margin.bottomHeight = 0;

                DwmExtendFrameIntoClientArea(this.Handle, ref margin);
            }
        }
    }
}