$source = @" using System; using System.Runtime.InteropServices; public class Hello { [StructLayout(LayoutKind.Sequential)] struct POINT { public int x; public int y; } [StructLayout(LayoutKind.Sequential)] struct MSG { public IntPtr hwnd; public uint message; public IntPtr wParam; public IntPtr lParam; public uint time; public POINT pt; } delegate IntPtr WndProcDelgate(IntPtr hWnd, uint uMsg, IntPtr wParam, IntPtr lParam); [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)] struct WNDCLASSEX { public uint cbSize; public uint style; public WndProcDelgate lpfnWndProc; public Int32 cbClsExtra; public Int32 cbWndExtra; public IntPtr hInstance; public IntPtr hIcon; public IntPtr hCursor; public IntPtr hbrBackground; public string lpszMenuName; public string lpszClassName; public IntPtr hIconSm; } [StructLayout(LayoutKind.Sequential)] struct RECT { public int Left; public int Top; public int Right; public int Bottom; } [StructLayout(LayoutKind.Sequential)] struct PAINTSTRUCT { public IntPtr hdc; public int fErase; public RECT rcPaint; public int fRestore; public int fIncUpdate; [MarshalAs(UnmanagedType.ByValArray, SizeConst = 32)] public byte[] rgbReserved; } const uint WS_OVERLAPPED = 0x00000000; const uint WS_POPUP = 0x80000000; const uint WS_CHILD = 0x40000000; const uint WS_MINIMIZE = 0x20000000; const uint WS_VISIBLE = 0x10000000; const uint WS_DISABLED = 0x08000000; const uint WS_CLIPSIBLINGS = 0x04000000; const uint WS_CLIPCHILDREN = 0x02000000; const uint WS_MAXIMIZE = 0x01000000; const uint WS_CAPTION = 0x00C00000; // WS_BORDER | WS_DLGFRAME const uint WS_BORDER = 0x00800000; const uint WS_DLGFRAME = 0x00400000; const uint WS_VSCROLL = 0x00200000; const uint WS_HSCROLL = 0x00100000; const uint WS_SYSMENU = 0x00080000; const uint WS_THICKFRAME = 0x00040000; const uint WS_GROUP = 0x00020000; const uint WS_TABSTOP = 0x00010000; const uint WS_MINIMIZEBOX = 0x00020000; const uint WS_MAXIMIZEBOX = 0x00010000; const uint WS_TILED = WS_OVERLAPPED; const uint WS_ICONIC = WS_MINIMIZE; const uint WS_SIZEBOX = WS_THICKFRAME; const uint WS_TILEDWINDOW = WS_OVERLAPPEDWINDOW; const uint WS_OVERLAPPEDWINDOW = WS_OVERLAPPED | WS_CAPTION | WS_SYSMENU | WS_THICKFRAME | WS_MINIMIZEBOX | WS_MAXIMIZEBOX; const uint WS_POPUPWINDOW = WS_POPUP | WS_BORDER | WS_SYSMENU; const uint WS_CHILDWINDOW = WS_CHILD; const uint WM_CREATE = 0x0001; const uint WM_DESTROY = 0x0002; const uint WM_PAINT = 0x000F; const uint WM_CLOSE = 0x0010; const uint WM_COMMAND = 0x0111; const uint COLOR_WINDOW = 5; const uint COLOR_BTNFACE = 15; const uint CS_VREDRAW = 0x0001; const uint CS_HREDRAW = 0x0002; const int CW_USEDEFAULT = -2147483648; // ((uint)0x80000000) const uint SW_SHOWDEFAULT = 10; const int IDI_APPLICATION = 32512; const int IDC_ARROW = 32512; [DllImport("user32.dll", CharSet = CharSet.Auto)] static extern IntPtr LoadCursor(IntPtr hInstance, IntPtr lpCursorName); [DllImport("user32.dll", CharSet = CharSet.Auto)] static extern IntPtr LoadIcon(IntPtr hInstance, IntPtr lpIconName); [DllImport("user32.dll", CharSet = CharSet.Auto)] static extern short RegisterClassEx(ref WNDCLASSEX pcWndClassEx); [DllImport("user32.dll", CharSet = CharSet.Auto)] static extern IntPtr CreateWindowEx(uint dwExStyle, string lpClassName, string lpWindowName, uint dwStyle, int x, int y, int nWidth, int nHeight, IntPtr hWndParent, IntPtr hMenu, IntPtr hInstance, IntPtr lpParam); [DllImport("user32.dll", CharSet = CharSet.Auto)] static extern bool ShowWindow(IntPtr hWnd, uint nCmdShow); [DllImport("user32.dll", CharSet = CharSet.Auto)] static extern bool UpdateWindow(IntPtr hWnd); [DllImport("user32.dll", CharSet = CharSet.Auto)] static extern int GetMessage(out MSG lpMsg, IntPtr hWnd, uint wMsgFilterMin, uint wMsgFilterMax); [DllImport("user32.dll", CharSet = CharSet.Auto)] static extern int TranslateMessage([In] ref MSG lpMsg); [DllImport("user32.dll", CharSet = CharSet.Auto)] static extern IntPtr DispatchMessage([In] ref MSG lpMsg); [DllImport("user32.dll", CharSet = CharSet.Auto)] static extern void PostQuitMessage(int nExitCode); [DllImport("user32.dll", CharSet = CharSet.Auto)] static extern IntPtr DefWindowProc(IntPtr hWnd, uint uMsg, IntPtr wParam, IntPtr lParam); [DllImport("user32.dll", CharSet = CharSet.Auto)] static extern IntPtr BeginPaint(IntPtr hWnd, out PAINTSTRUCT lpPaint); [DllImport("user32.dll", CharSet = CharSet.Auto)] static extern IntPtr EndPaint(IntPtr hWnd, ref PAINTSTRUCT lpPaint); [DllImport("gdi32.dll", CharSet = CharSet.Auto)] static extern IntPtr TextOut( IntPtr hdc, int x, int y, string lpString, int nCount ); [DllImport("kernel32.dll", CharSet = CharSet.Auto)] static extern IntPtr GetModuleHandle(string lpModuleName); static IntPtr WndProc(IntPtr hWnd, uint uMsg, IntPtr wParam, IntPtr lParam) { PAINTSTRUCT ps = new PAINTSTRUCT(); IntPtr hdc; string strMessage = "Hello, Win32 GUI(PowerShell) World!"; switch (uMsg) { case WM_PAINT: hdc = BeginPaint( hWnd, out ps ); TextOut( hdc, 0, 0, strMessage, strMessage.Length ); EndPaint( hWnd, ref ps ); break; case WM_DESTROY: PostQuitMessage(0); break; default: return DefWindowProc(hWnd, uMsg, wParam, lParam); } return IntPtr.Zero; } static int WinMain() { IntPtr hInstance = Marshal.GetHINSTANCE(typeof(Hello).Module); const string CLASS_NAME = "helloWindow"; const string WINDOW_NAME = "Hello, World!"; WNDCLASSEX wcex = new WNDCLASSEX(); wcex.cbSize = (uint)Marshal.SizeOf(wcex); wcex.style = CS_HREDRAW | CS_VREDRAW; wcex.lpfnWndProc = new WndProcDelgate(WndProc); wcex.cbClsExtra = 0; wcex.cbWndExtra = 0; wcex.hInstance = hInstance; wcex.hIcon = LoadIcon(hInstance, new IntPtr(IDI_APPLICATION)); wcex.hCursor = LoadIcon(hInstance, new IntPtr(IDC_ARROW)); wcex.hbrBackground = new IntPtr(COLOR_WINDOW + 1); wcex.lpszMenuName = ""; wcex.lpszClassName = CLASS_NAME; wcex.hIconSm = IntPtr.Zero; RegisterClassEx(ref wcex); IntPtr hWnd = CreateWindowEx( 0, wcex.lpszClassName, WINDOW_NAME, WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, 640, 480, IntPtr.Zero, IntPtr.Zero, wcex.hInstance, IntPtr.Zero); ShowWindow(hWnd, SW_SHOWDEFAULT); UpdateWindow(hWnd); MSG msg = new MSG(); while (GetMessage(out msg, IntPtr.Zero, 0, 0) != 0) { TranslateMessage(ref msg); DispatchMessage(ref msg); } return (int)msg.wParam; } [STAThread] public static int Main() { return WinMain(); } } "@ Add-Type -Language CSharp -TypeDefinition $source -ReferencedAssemblies ("System.Drawing", "System.Windows.Forms" ) [void][Hello]::Main()