SystemTrayMenu/NativeDllImport/ShowInactiveTopmost.cs

// <copyright file="ShowInactiveTopmost.cs" company="PlaceholderCompany">
// Copyright (c) PlaceholderCompany. All rights reserved.
// </copyright>

namespace SystemTrayMenu.DllImports
{
    using System.Runtime.InteropServices;
    using System.Windows.Forms;

    /// <summary>
    /// wraps the methodcalls to native windows dll's.
    /// </summary>
    public static partial class NativeMethods
    {
        private const int SW_SHOWNOACTIVATE = 4;
        private const int HWND_TOPMOST = -1;
        private const uint SWP_NOACTIVATE = 0x0010;

        public static void User32ShowInactiveTopmost(Form form)
        {
            if (form != null)
            {
                _ = ShowWindow(form.Handle, SW_SHOWNOACTIVATE);
                SetWindowPos(
                    form.Handle.ToInt32(),
                    HWND_TOPMOST,
                    form.Left,
                    form.Top,
                    form.Width,
                    form.Height,
                    SWP_NOACTIVATE);
            }
        }

        [DllImport("user32.dll", EntryPoint = "SetWindowPos", SetLastError = true, CharSet = CharSet.Unicode)]
        [DefaultDllImportSearchPaths(DllImportSearchPath.UserDirectories)]
        private static extern bool SetWindowPos(
             int hWnd,             // Window handle
             int hWndInsertAfter,  // Placement-order handle
             int X,                // Horizontal position
             int Y,                // Vertical position
             int cx,               // Width
             int cy,               // Height
             uint uFlags);         // Window positioning flags
    }
}