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(300300); 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