NativeMethods

gistfile1.cs

public static class NativeMethods
    {
        public static IntPtr GetAndSetWindowFullScreenWindowed(string windowTitle)
        {
            var minecraftWindow = FindWindowEx(IntPtr.Zero, IntPtr.Zero, null, windowTitle);
            
            if (minecraftWindow == IntPtr.Zero)
            {
                return IntPtr.Zero;
            }

            SetWindowFullScreenWindowed(minecraftWindow);

            return minecraftWindow;
        }

        public static void SetWindowFullScreenWindowed(IntPtr minecraftWindow)
        {
            var lStyle = GetWindowLong(minecraftWindow, WS.GWL_STYLE);
            // remove the window crap
            lStyle &= ~(WS.WS_CAPTION | WS.WS_BORDER | WS.WS_DLGFRAME | WS.WS_SIZEBOX | WS.WS_THICKFRAME);

            SetWindowLong(minecraftWindow, WS.GWL_STYLE, lStyle);

            var bounds = Screen.PrimaryScreen.Bounds;
            SetWindowPos(minecraftWindow, new IntPtr(0), bounds.X, bounds.Y, bounds.Width, bounds.Height, SetWindowPosFlags.ShowWindow);
        }

        #region Native Methods and Types

        [DllImport("user32.dll", SetLastError = true)]
        public static extern IntPtr FindWindowEx(IntPtr hwndParent, IntPtr hwndChildAfter, string lpszClass, string lpszWindow);

        [DllImport("user32.dll", SetLastError = true)]
        public static extern IntPtr SetParent(IntPtr hWndChild, IntPtr hWndNewParent);

        [DllImport("user32.dll")]
        public static extern UInt32 SetWindowLong(IntPtr hWnd, Int32 nIndex, UInt32 dwNewLong);

        [DllImport("user32.dll", SetLastError = true)]
        public static extern UInt32 GetWindowLong(IntPtr hWnd, Int32 nIndex);

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


        public static class WS
        {
            public const Int32 GWL_ID = (-12);
            public const Int32 GWL_STYLE = (-16);
            public const Int32 GWL_EXSTYLE = (-20);

            // Window Styles 
            public const UInt32 WS_OVERLAPPED = 0;
            public const UInt32 WS_POPUP = 0x80000000;
            public const UInt32 WS_CHILD = 0x40000000;
            public const UInt32 WS_MINIMIZE = 0x20000000;
            public const UInt32 WS_VISIBLE = 0x10000000;
            public const UInt32 WS_DISABLED = 0x8000000;
            public const UInt32 WS_CLIPSIBLINGS = 0x4000000;
            public const UInt32 WS_CLIPCHILDREN = 0x2000000;
            public const UInt32 WS_MAXIMIZE = 0x1000000;
            public const UInt32 WS_CAPTION = 0xC00000;      // WS_BORDER or WS_DLGFRAME  
            public const UInt32 WS_BORDER = 0x800000;
            public const UInt32 WS_DLGFRAME = 0x400000;
            public const UInt32 WS_VSCROLL = 0x200000;
            public const UInt32 WS_HSCROLL = 0x100000;
            public const UInt32 WS_SYSMENU = 0x80000;
            public const UInt32 WS_THICKFRAME = 0x40000;
            public const UInt32 WS_GROUP = 0x20000;
            public const UInt32 WS_TABSTOP = 0x10000;
            public const UInt32 WS_MINIMIZEBOX = 0x20000;
            public const UInt32 WS_MAXIMIZEBOX = 0x10000;
            public const UInt32 WS_TILED = WS_OVERLAPPED;
            public const UInt32 WS_ICONIC = WS_MINIMIZE;
            public const UInt32 WS_SIZEBOX = WS_THICKFRAME;

            // Extended Window Styles 
            public const UInt32 WS_EX_DLGMODALFRAME = 0x0001;
            public const UInt32 WS_EX_NOPARENTNOTIFY = 0x0004;
            public const UInt32 WS_EX_TOPMOST = 0x0008;
            public const UInt32 WS_EX_ACCEPTFILES = 0x0010;
            public const UInt32 WS_EX_TRANSPARENT = 0x0020;
            public const UInt32 WS_EX_MDICHILD = 0x0040;
            public const UInt32 WS_EX_TOOLWINDOW = 0x0080;
            public const UInt32 WS_EX_WINDOWEDGE = 0x0100;
            public const UInt32 WS_EX_CLIENTEDGE = 0x0200;
            public const UInt32 WS_EX_CONTEXTHELP = 0x0400;
            public const UInt32 WS_EX_RIGHT = 0x1000;
            public const UInt32 WS_EX_LEFT = 0x0000;
            public const UInt32 WS_EX_RTLREADING = 0x2000;
            public const UInt32 WS_EX_LTRREADING = 0x0000;
            public const UInt32 WS_EX_LEFTSCROLLBAR = 0x4000;
            public const UInt32 WS_EX_RIGHTSCROLLBAR = 0x0000;
            public const UInt32 WS_EX_CONTROLPARENT = 0x10000;
            public const UInt32 WS_EX_STATICEDGE = 0x20000;
            public const UInt32 WS_EX_APPWINDOW = 0x40000;
            public const UInt32 WS_EX_OVERLAPPEDWINDOW = (WS_EX_WINDOWEDGE | WS_EX_CLIENTEDGE);
            public const UInt32 WS_EX_PALETTEWINDOW = (WS_EX_WINDOWEDGE | WS_EX_TOOLWINDOW | WS_EX_TOPMOST);
            public const UInt32 WS_EX_LAYERED = 0x00080000;
            public const UInt32 WS_EX_NOINHERITLAYOUT = 0x00100000; // Disable inheritence of mirroring by children
            public const UInt32 WS_EX_LAYOUTRTL = 0x00400000; // Right to left mirroring
            public const UInt32 WS_EX_COMPOSITED = 0x02000000;
            public const UInt32 WS_EX_NOACTIVATE = 0x08000000;
        }

        [Flags()]
        public enum SetWindowPosFlags : uint
        {
            /// <summary>If the calling thread and the thread that owns the window are attached to different input queues, 
            /// the system posts the request to the thread that owns the window. This prevents the calling thread from 
            /// blocking its execution while other threads process the request.</summary>
            /// <remarks>SWP_ASYNCWINDOWPOS</remarks>
            SynchronousWindowPosition = 0x4000,
            /// <summary>Prevents generation of the WM_SYNCPAINT message.</summary>
            /// <remarks>SWP_DEFERERASE</remarks>
            DeferErase = 0x2000,
            /// <summary>Draws a frame (defined in the window's class description) around the window.</summary>
            /// <remarks>SWP_DRAWFRAME</remarks>
            DrawFrame = 0x0020,
            /// <summary>Applies new frame styles set using the SetWindowLong function. Sends a WM_NCCALCSIZE message to 
            /// the window, even if the window's size is not being changed. If this flag is not specified, WM_NCCALCSIZE 
            /// is sent only when the window's size is being changed.</summary>
            /// <remarks>SWP_FRAMECHANGED</remarks>
            FrameChanged = 0x0020,
            /// <summary>Hides the window.</summary>
            /// <remarks>SWP_HIDEWINDOW</remarks>
            HideWindow = 0x0080,
            /// <summary>Does not activate the window. If this flag is not set, the window is activated and moved to the 
            /// top of either the topmost or non-topmost group (depending on the setting of the hWndInsertAfter 
            /// parameter).</summary>
            /// <remarks>SWP_NOACTIVATE</remarks>
            DoNotActivate = 0x0010,
            /// <summary>Discards the entire contents of the client area. If this flag is not specified, the valid 
            /// contents of the client area are saved and copied back into the client area after the window is sized or 
            /// repositioned.</summary>
            /// <remarks>SWP_NOCOPYBITS</remarks>
            DoNotCopyBits = 0x0100,
            /// <summary>Retains the current position (ignores X and Y parameters).</summary>
            /// <remarks>SWP_NOMOVE</remarks>
            IgnoreMove = 0x0002,
            /// <summary>Does not change the owner window's position in the Z order.</summary>
            /// <remarks>SWP_NOOWNERZORDER</remarks>
            DoNotChangeOwnerZOrder = 0x0200,
            /// <summary>Does not redraw changes. If this flag is set, no repainting of any kind occurs. This applies to 
            /// the client area, the nonclient area (including the title bar and scroll bars), and any part of the parent 
            /// window uncovered as a result of the window being moved. When this flag is set, the application must 
            /// explicitly invalidate or redraw any parts of the window and parent window that need redrawing.</summary>
            /// <remarks>SWP_NOREDRAW</remarks>
            DoNotRedraw = 0x0008,
            /// <summary>Same as the SWP_NOOWNERZORDER flag.</summary>
            /// <remarks>SWP_NOREPOSITION</remarks>
            DoNotReposition = 0x0200,
            /// <summary>Prevents the window from receiving the WM_WINDOWPOSCHANGING message.</summary>
            /// <remarks>SWP_NOSENDCHANGING</remarks>
            DoNotSendChangingEvent = 0x0400,
            /// <summary>Retains the current size (ignores the cx and cy parameters).</summary>
            /// <remarks>SWP_NOSIZE</remarks>
            IgnoreResize = 0x0001,
            /// <summary>Retains the current Z order (ignores the hWndInsertAfter parameter).</summary>
            /// <remarks>SWP_NOZORDER</remarks>
            IgnoreZOrder = 0x0004,
            /// <summary>Displays the window.</summary>
            /// <remarks>SWP_SHOWWINDOW</remarks>
            ShowWindow = 0x0040,
        }

        #endregion
    }