Suspending Screensaver in C#

Question

How would I suspend the screensaver in my C# application? Would I have to use DirectX or COM?

jucy · Answer

"parent.Text = "Screensaver suspended..."; " code dose work on my XP Machine, but screensaver also works. --; Does it really suspend screensaver? Thank you, Jucy

marvin7 · Answer

I can't thank you enough... Hopefully, I can return the favor someday.

bilnaad · Answer

Here you have two classes. The first is VisualMedia wich is just a form from a project of mine. The second is MessageListener wich handles the messages send to the assign form by windows. ----VisualMedia.cs------------------------ using System; using System.Windows.Forms; namespace System { public class VisualMedia : System.Windows.Forms.Form { private MessageListener msgListener = null; public VisualMedia() { InitializeComponent(); msgListener = new MessageListener(this); } #region Windows Form Designer generated code /// /// Required method for Designer support - do not modify /// the contents of this method with the code editor. /// private void InitializeComponent() { // // VisualMedia // this.AutoScaleBaseSize = new System.Drawing.Size(5, 13); this.ClientSize = new System.Drawing.Size(632, 447); this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedSingle; this.Name = "VisualMedia"; this.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen; this.Text = "Visual Media"; } #endregion public static void Main() { Application.EnableVisualStyles(); Application.Run( new VisualMedia() ); } } } --------------------------------------------- ----MessageListener.cs------------------- using System; using System.Windows.Forms; namespace System { #region " System Commands " public enum SC : int { SIZE = 0xF000, MOVE = 0xF010, MINIMIZE = 0xF020, MAXIMIZE = 0xF030, NEXTWINDOW = 0xF040, PREVWINDOW = 0xF050, CLOSE = 0xF060, VSCROLL = 0xF070, HSCROLL = 0xF080, MOUSEMENU = 0xF090, KEYMENU = 0xF100, ARRANGE = 0xF110, RESTORE = 0xF120, TASKLIST = 0xF130, SCREENSAVE = 0xF140, HOTKEY = 0xF150, DEFAULT = 0xF160, MONITORPOWER = 0xF170, CONTEXTHELP = 0xF180, SEPARATOR = 0xF00F } #endregion #region " Window Messages " /// /// Window Messages /// public enum WM : int { ACTIVATE = 0x0006, ACTIVATEAPP = 0x001C, AFXFIRST = 0x0360, AFXLAST = 0x037F, APP = 0x8000, ASKCBFORMATNAME = 0x030C, CANCELJOURNAL = 0x004B, CANCELMODE = 0x001F, CAPTURECHANGED = 0x0215, CHANGECBCHAIN = 0x030D, CHAR = 0x0102, CHARTOITEM = 0x002F, CHILDACTIVATE = 0x0022, CLEAR = 0x0303, CLOSE = 0x0010, COMMAND = 0x0111, COMPACTING = 0x0041, COMPAREITEM = 0x0039, CONTEXTMENU = 0x007B, COPY = 0x0301, COPYDATA = 0x004A, CREATE = 0x0001, CTLCOLORBTN = 0x0135, CTLCOLORDLG = 0x0136, CTLCOLOREDIT = 0x0133, CTLCOLORLISTBOX = 0x0134, CTLCOLORMSGBOX = 0x0132, CTLCOLORSCROLLBAR = 0x0137, CTLCOLORSTATIC = 0x0138, CUT = 0x0300, DEADCHAR = 0x0103, DELETEITEM = 0x002D, DESTROY = 0x0002, DESTROYCLIPBOARD = 0x0307, DEVICECHANGE = 0x0219, DEVMODECHANGE = 0x001B, DISPLAYCHANGE = 0x007E, DRAWCLIPBOARD = 0x0308, DRAWITEM = 0x002B, DROPFILES = 0x0233, ENABLE = 0x000A, ENDSESSION = 0x0016, ENTERIDLE = 0x0121, ENTERMENULOOP = 0x0211, ENTERSIZEMOVE = 0x0231, ERASEBKGND = 0x0014, EXITMENULOOP = 0x0212, EXITSIZEMOVE = 0x0232, FONTCHANGE = 0x001D, GETDLGCODE = 0x0087, GETFONT = 0x0031, GETHOTKEY = 0x0033, GETICON = 0x007F, GETMINMAXINFO = 0x0024, GETOBJECT = 0x003D, GETTEXT = 0x000D, GETTEXTLENGTH = 0x000E, HANDHELDFIRST = 0x0358, HANDHELDLAST = 0x035F, HELP = 0x0053, HOTKEY = 0x0312, HSCROLL = 0x0114, HSCROLLCLIPBOARD = 0x030E, ICONERASEBKGND = 0x0027, IME_CHAR = 0x0286, IME_COMPOSITION = 0x010F, IME_COMPOSITIONFULL = 0x0284, IME_CONTROL = 0x0283, IME_ENDCOMPOSITION = 0x010E, IME_KEYDOWN = 0x0290, IME_KEYLAST = 0x010F, IME_KEYUP = 0x0291, IME_NOTIFY = 0x0282, IME_REQUEST = 0x0288, IME_SELECT = 0x0285, IME_SETCONTEXT = 0x0281, IME_STARTCOMPOSITION = 0x010D, INITDIALOG = 0x0110, INITMENU = 0x0116, INITMENUPOPUP = 0x0117, INPUTLANGCHANGE = 0x0051, INPUTLANGCHANGEREQUEST = 0x0050, KEYDOWN = 0x0100, KEYFIRST = 0x0100, KEYLAST = 0x0108, KEYUP = 0x0101, KILLFOCUS = 0x0008, LBUTTONDBLCLK = 0x0203, LBUTTONDOWN = 0x0201, LBUTTONUP = 0x0202, MBUTTONDBLCLK = 0x0209, MBUTTONDOWN = 0x0207, MBUTTONUP = 0x0208, MDIACTIVATE = 0x0222, MDICASCADE = 0x0227, MDICREATE = 0x0220, MDIDESTROY = 0x0221, MDIGETACTIVE = 0x0229, MDIICONARRANGE = 0x0228, MDIMAXIMIZE = 0x0225, MDINEXT = 0x0224, MDIREFRESHMENU = 0x0234, MDIRESTORE = 0x0223, MDISETMENU = 0x0230, MDITILE = 0x0226, MEASUREITEM = 0x002C, MENUCHAR = 0x0120, MENUCOMMAND = 0x0126, MENUDRAG = 0x0123, MENUGETOBJECT = 0x0124, MENURBUTTONUP = 0x0122, MENUSELECT = 0x011F, MOUSEACTIVATE = 0x0021, MOUSEFIRST = 0x0200, MOUSEHOVER = 0x02A1, MOUSELAST = 0x020A, MOUSELEAVE = 0x02A3, MOUSEMOVE = 0x0200, MOUSEWHEEL = 0x020A, MOVE = 0x0003, MOVING = 0x0216, NCACTIVATE = 0x0086, NCCALCSIZE = 0x0083, NCCREATE = 0x0081, NCDESTROY = 0x0082, NCHITTEST = 0x0084, NCLBUTTONDBLCLK = 0x00A3, NCLBUTTONDOWN = 0x00A1, NCLBUTTONUP = 0x00A2, NCMBUTTONDBLCLK = 0x00A9, NCMBUTTONDOWN = 0x00A7, NCMBUTTONUP = 0x00A8, NCMOUSEHOVER = 0x02A0, NCMOUSEMOVE = 0x00A0, NCPAINT = 0x0085, NCRBUTTONDBLCLK = 0x00A6, NCRBUTTONDOWN = 0x00A4, NCRBUTTONUP = 0x00A5, NEXTDLGCTL = 0x0028, NEXTMENU = 0x0213, NOTIFY = 0x004E, NOTIFYFORMAT = 0x0055, NULL = 0x0000, PAINT = 0x000F, PAINTCLIPBOARD = 0x0309, PAINTICON = 0x0026, PALETTECHANGED = 0x0311, PALETTEISCHANGING = 0x0310, PARENTNOTIFY = 0x0210, PASTE = 0x0302, PENWINFIRST = 0x0380, PENWINLAST = 0x038F, POWER = 0x0048, PRINT = 0x0317, PRINTCLIENT = 0x0318, QUERYDRAGICON = 0x0037, QUERYENDSESSION = 0x0011, QUERYNEWPALETTE = 0x030F, QUERYOPEN = 0x0013, QUEUESYNC = 0x0023, QUIT = 0x0012, RBUTTONDBLCLK = 0x0206, RBUTTONDOWN = 0x0204, RBUTTONUP = 0x0205, RENDERALLFORMATS = 0x0306, RENDERFORMAT = 0x0305, SETCURSOR = 0x0020, SETFOCUS = 0x0007, SETFONT = 0x0030, SETHOTKEY = 0x0032, SETICON = 0x0080, SETREDRAW = 0x000B, SETTEXT = 0x000C, SETTINGCHANGE = 0x001A, SHOWWINDOW = 0x0018, SIZE = 0x0005, SIZECLIPBOARD = 0x030B, SIZING = 0x0214, SPOOLERSTATUS = 0x002A, STYLECHANGED = 0x007D, STYLECHANGING = 0x007C, SYNCPAINT = 0x0088, SYSCHAR = 0x0106, SYSCOLORCHANGE = 0x0015, SYSCOMMAND = 0x0112, SYSDEADCHAR = 0x0107, SYSKEYDOWN = 0x0104, SYSKEYUP = 0x0105, TCARD = 0x0052, TIMECHANGE = 0x001E, TIMER = 0x0113, UNDO = 0x0304, UNINITMENUPOPUP = 0x0125, USER = 0x0400, USERCHANGED = 0x0054, VKEYTOITEM = 0x002E, VSCROLL = 0x0115, VSCROLLCLIPBOARD = 0x030A, WINDOWPOSCHANGED = 0x0047, WINDOWPOSCHANGING = 0x0046, WININICHANGE = 0x001A } #endregion /// /// Summary description for MessageListener. /// public class MessageListener : NativeWindow { #region " Constructor+ " private Form parent = null; public MessageListener(Form parent) { this.parent = parent; this.parent.HandleCreated += new EventHandler(OnHandleCreated); this.parent.HandleDestroyed += new EventHandler(OnHandleDestroyed); } internal void OnHandleCreated(object sender ,EventArgs e) { this.AssignHandle( ((Form)sender).Handle ); } internal void OnHandleDestroyed(object sender ,EventArgs e) { this.ReleaseHandle(); } #endregion protected override void WndProc(ref Message m) { switch( (WM)m.Msg ) { case WM.SYSCOMMAND: { SC sysCommand = (SC)m.WParam.ToInt32(); if (sysCommand == SC.SCREENSAVE) { parent.Text = "Screensaver suspended..."; return; } }break; } base.WndProc(ref m); } } } ---------------------------------------------

bilnaad · Answer

Sorry my mistake. You don't need to assign a IntPtr(0) to the message.Result Just return from the WndProc Method. I will post A simpler version in a few minutes. It will also include the full enums of SC(system command) and WM(window message). please hold..... :)

marvin7 · Answer

I think I understand, but I haven't had too much luck thus far... I combined the example given in your link with the code you gave me... but it hasn't worked thus far. Here it is: ///////////// ///////////// using System; using System.Drawing; using System.Windows.Forms; using System.Runtime.InteropServices; namespace NativeWindowApplication { // Summary description for Form1. public class Form1 : System.Windows.Forms.Form { private MyNativeWindowListener nwl; private MyNativeWindow nw; internal void ApplicationActived(bool ApplicationActivated) { // The application has been activated or deactivated System.Diagnostics.Debug.WriteLine("Application Active = " + ApplicationActivated.ToString()); } public Form1() { this.Size = new System.Drawing.Size(300,300); this.Text = "Form1"; nwl = new MyNativeWindowListener(this); nw = new MyNativeWindow(this); } // The main entry point for the application. [STAThread] static void Main() { Application.Run(new Form1()); } } // NativeWindow class to listen to operating system messages. public class MyNativeWindowListener: NativeWindow { // Constant value was found in the "windows.h" header file. private const int WM_ACTIVATEAPP = 0x001C; private const int WM_SYSCOMMAND = 0x0112; private const int SC_SCREENSAVE = 0xF140; private Form1 parent; public MyNativeWindowListener(Form1 parent) { parent.HandleCreated += new EventHandler(this.OnHandleCreated); parent.HandleDestroyed+= new EventHandler(this.OnHandleDestroyed); this.parent = parent; } // Listen for the control's window creation and then hook into it. internal void OnHandleCreated(object sender, EventArgs e) { // Window is now created, assign handle to NativeWindow. AssignHandle(((Form1)sender).Handle); } internal void OnHandleDestroyed(object sender, EventArgs e) { // Window was destroyed, release hook. ReleaseHandle(); } [System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name="FullTrust")] protected override void WndProc(ref Message m) { // Listen for operating system messages switch (m.Msg) { case WM_ACTIVATEAPP: // Notify the form that this message was received. // Application is activated or deactivated, // based upon the WParam parameter. parent.ApplicationActived(((int)m.WParam != 0)); break; case WM_SYSCOMMAND: if (m.WParam.ToInt32() == SC_SCREENSAVE) m.Result = new IntPtr(0); break; } base.WndProc(ref m); } } // MyNativeWindow class to create a window given a class name. public class MyNativeWindow: NativeWindow { // Constant values were found in the "windows.h" header file. private const int WS_CHILD = 0x40000000, private const int WS_VISIBLE = 0x10000000, private const int WM_ACTIVATEAPP = 0x001C; private const int WM_SYSCOMMAND = 0x0112; private const int SC_SCREENSAVE = 0xF140; private int windowHandle; public MyNativeWindow(Form parent) { CreateParams cp = new CreateParams(); // Fill in the CreateParams details. cp.Caption = "Click here"; cp.ClassName = "Button"; // Set the position on the form cp.X = 100; cp.Y = 100; cp.Height = 100; cp.Width = 100; // Specify the form as the parent. cp.Parent = parent.Handle; // Create as a child of the specified parent cp.Style = WS_CHILD | WS_VISIBLE; // Create the actual window this.CreateHandle(cp); } // Listen to when the handle changes to keep the variable in sync [System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name="FullTrust")] protected override void OnHandleChange() { windowHandle = (int)this.Handle; } [System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name="FullTrust")] protected override void WndProc(ref Message m) { // Listen for messages that are sent to the button window. Some messages are sent // to the parent window instead of the button's window. switch (m.Msg) { case WM_ACTIVATEAPP: // Do something here in response to messages break; case WM_SYSCOMMAND: if (m.WParam.ToInt32() == SC_SCREENSAVE) { m.Result = new IntPtr(0); } break; } base.WndProc(ref m); } } }

bilnaad · Answer

If you want to suspend the screensaver you will need to take advantage of the nativeWindow class in System.Windows.Forms. You could create a messageListener with a class that inherits the nativeWindow and override it's WndProc (Window procedure) method. Look here for more details: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/frlrfsystemwindowsformsnativewindowclasstopic.asp In the C# sample you can delete the MyNativeWindow class. because it has no use in what you want. In the WndProc(ref Message m) you can check if windows is trying to activate the screensaver. You will need two constants for that: const int WM_SYSCOMMAND = 0x0112; const int SC_SCREENSAVE = 0xF140; With these you could check the situation. switch( m.Msg) { case WM_SYSCOMMAND: { if (m.wParam.ToInt32() == SC_SCREENSAVE) { m.Result = new IntPtr(0); } } } If you feel you don't quite understand this you could mail me and I will send you the code to suspend the screensaver. Cheers

Suspending Screensaver in C#

Answers (6)