WindowExtensions.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;
using System.Windows;

namespace NewProcessMonitoring
{
    internal static class WindowExtensions
    {
        // from winuser.h
        private const int GWL_STYLE = -16,
                          WS_MAXIMIZEBOX = 0x10000,
                          WS_MINIMIZEBOX = 0x20000;

        [DllImport("user32.dll")]
        extern private static int GetWindowLong(IntPtr hwnd, int index);

        [DllImport("user32.dll")]
        extern private static int SetWindowLong(IntPtr hwnd, int index, int value);

        internal static void HideMinimizeAndMaximizeButtons(this Window window)
        {
            IntPtr hwnd = new System.Windows.Interop.WindowInteropHelper(window).Handle;
            var currentStyle = GetWindowLong(hwnd, GWL_STYLE);

            SetWindowLong(hwnd, GWL_STYLE, (currentStyle & ~WS_MAXIMIZEBOX & ~WS_MINIMIZEBOX));
        }
    }
}