inabox/inabox.wpf/SafeNativeMethods.cs

using System.Runtime.InteropServices;

namespace InABox.WPF
{
    public sealed class SafeNativeMethods
    {
        [Flags]
        public enum SetWindowPosFlags : uint
        {
            SWP_NOACTIVATE = 0x0010,
            SWP_NOMOVE = 0x0002,
            SWP_NOSIZE = 0x0001
        }

        public const int WS_EX_NOACTIVATE = 0x08000000;
        public const int ULW_ALPHA = 0x00000002;
        public const int AC_SRC_OVER = 0x00000000;
        public const int AC_SRC_ALPHA = 0x00000001;
        public static readonly IntPtr HWND_TOP = new(0);

        [DllImport("user32.dll", ExactSpelling = true, SetLastError = true)]
        public static extern bool UpdateLayeredWindow(IntPtr hwnd, IntPtr hdcDst, IntPtr pptDst, IntPtr psize, IntPtr hdcSrc, IntPtr pptSrc,
            uint crKey,
            [In] ref BLENDFUNCTION pblend, uint dwFlags);

        [DllImport("user32.dll", ExactSpelling = true, SetLastError = true)]
        [return: MarshalAs(UnmanagedType.Bool)]
        public static extern bool SetWindowPos(IntPtr hWnd, IntPtr hWndInsertAfter, int X, int Y, int cx, int cy, SetWindowPosFlags uFlags);

        public struct BLENDFUNCTION
        {
            public byte BlendOp;
            public byte BlendFlags;
            public byte SourceConstantAlpha;
            public byte AlphaFormat;
        }
    }
}