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Turn Monitor completely off (not Standby) programmatically [duplicate]

Is it programmatically possible to turn a monitor on/off through code (C#)?

Did you even try googling it?
First hit:
http://www.codeproject.com/KB/cs/Monitor_management_guide.aspx
I am not surprised you need to use some DLL's supplied by Windows.
(I guessed you needed a C# solution, because that's the only tag you applied).
EDIT February 8th 2013:
It was mentioned that the solution no longer worked under Windows 7 en 8. Well here is one that works nicely under Windows 7, haven't tried Windows 8 yet.
http://cocoa.ninja/posts/Turn-off-your-monitor-in-Csharp.html
namespace MonitorOff {
public enum MonitorState {
MonitorStateOn = -1,
MonitorStateOff = 2,
MonitorStateStandBy = 1
}
public partial class Form1 : Form {
[DllImport("user32.dll")]
private static extern int SendMessage(int hWnd, int hMsg, int wParam, int lParam);
public Form1() {
InitializeComponent();
SystemEvents.SessionSwitch += SystemEvents_SessionSwitch;
}
void SystemEvents_SessionSwitch(object sender, SessionSwitchEventArgs e) {
SetMonitorInState(MonitorState.MonitorStateOff);
}
private void button1_Click(object sender, EventArgs e) {
SetMonitorInState(MonitorState.MonitorStateOff);
}
private void SetMonitorInState(MonitorState state) {
SendMessage(0xFFFF, 0x112, 0xF170, (int)state);
}
}
}

The answer https://stackoverflow.com/a/713504/636189 above works great for turning off a Windows 7/8 monitor but not for waking it up. On those systems you'll need to do something hackish like this (as found https://stackoverflow.com/a/14171736/636189):
[DllImport("user32.dll")]
static extern void mouse_event(Int32 dwFlags, Int32 dx, Int32 dy, Int32 dwData, UIntPtr dwExtraInfo);
private const int MOUSEEVENTF_MOVE = 0x0001;
private void Wake(){
mouse_event(MOUSEEVENTF_MOVE, 0, 1, 0, UIntPtr.Zero);
Sleep(40);
mouse_event(MOUSEEVENTF_MOVE, 0, -1, 0, UIntPtr.Zero);
}

Press the on/off button
If you want to do it in code, apparently this is possible in the Win32 API:
SendMessage hWnd, WM_SYSCOMMAND, SC_MONITORPOWER, param
where WM_SYSCOMMAND = 0x112 and
SC_MONITORPOWER = 0xF170 and
param indicates the mode to put the monitor in:
-1 : on
2 : off
1 : energy saving mode
hWnd can be a handle for any window - so if you have a Form, something like this should work
int WM_SYSCOMMAND = 0x112;
int SC_MONITORPOWER = 0xF170;
[DllImport("user32.dll", CharSet = CharSet.Auto)]
private static extern int SendMessage(IntPtr hWnd, int wMsg, IntPtr wParam, IntPtr lParam);
public static void Main(string[] args)
{
Form f = new Form();
bool turnOff = true; //set true if you want to turn off, false if on
SendMessage(f.Handle, WM_SYSCOMMAND, (IntPtr)SC_MONITORPOWER, (IntPtr)(turnOff ? 2 : -1));
}
Note I haven't actually tried this...

For who wants this functionality on a console application:
using System;
using System.Runtime.InteropServices;
using System.Timers;
namespace TurnScreenOFF
{
class Program
{
private static int WM_SYSCOMMAND = 0x0112;
private static uint SC_MONITORPOWER = 0xF170;
public static void Main(string[] args)
{
SendMessage(GetConsoleWindow(), WM_SYSCOMMAND, (IntPtr)SC_MONITORPOWER, (IntPtr)2);
}
[DllImport("kernel32.dll")]
static extern IntPtr GetConsoleWindow();
[DllImport("user32.dll", CharSet = CharSet.Auto)]
private static extern int SendMessage(IntPtr hWnd, int wMsg, IntPtr wParam, IntPtr lParam);
}
}
Adaptated and tested. 100% working on Windows 8.

This code can be useful for turning on and turning off.. It worked in Windows 7 also.
private int SC_MONITORPOWER = 0xF170;
private uint WM_SYSCOMMAND = 0x0112;
[DllImport("user32.dll")]
static extern IntPtr SendMessage(IntPtr hWnd, uint Msg, IntPtr wParam, IntPtr lParam);
enum MonitorState
{
ON = -1,
OFF = 2,
STANDBY = 1
}
private void SetMonitorState(MonitorState state)
{
Form frm = new Form();
SendMessage(frm.Handle, WM_SYSCOMMAND, (IntPtr)SC_MONITORPOWER, (IntPtr)state);
}
For calling the function you must do like:
SetMonitorState(MonitorState.ON);
OR
SetMonitorState(MonitorState.OFF);
Note: This code tested in WPF Application. With the below namespaces:
using System.Runtime.InteropServices;
using System.Windows.Forms;

I could not find a copy paste example, so created one myself, dont forget to add a reference to System.Windows.Forms.
using System;
using System.Runtime.InteropServices;
using System.Threading;
using System.Windows.Forms;
namespace monitor_on_off
{
class Program
{
[DllImport("user32.dll")]
static extern IntPtr SendMessage(IntPtr hWnd, int msg, IntPtr wParam, IntPtr lParam);
[DllImport("user32.dll")]
static extern void mouse_event(Int32 dwFlags, Int32 dx, Int32 dy, Int32 dwData, UIntPtr dwExtraInfo);
private const int WmSyscommand = 0x0112;
private const int ScMonitorpower = 0xF170;
private const int MonitorShutoff = 2;
private const int MouseeventfMove = 0x0001;
public static void MonitorOff(IntPtr handle)
{
SendMessage(handle, WmSyscommand, (IntPtr)ScMonitorpower, (IntPtr)MonitorShutoff);
}
private static void MonitorOn()
{
mouse_event(MouseeventfMove, 0, 1, 0, UIntPtr.Zero);
Thread.Sleep(40);
mouse_event(MouseeventfMove, 0, -1, 0, UIntPtr.Zero);
}
static void Main()
{
var form = new Form();
while (true)
{
MonitorOff(form.Handle);
Thread.Sleep(5000);
MonitorOn();
Thread.Sleep(5000);
}
}
}
}

I have gone through every single method that everyone has published for putting a monitor to sleep and waking it later at some other time. Granted the SendMessage() does work with Windows XP but it doesn't wake the monitor after the monitor has been a sleep for a period of time. I have tried using C#, DOS, scripts for playing with power profiles, and Powershell. Eventually I gave up and went back to the beginning and my first thought was proven correct. You need to use the PostMessage() after the monitor has been turned off, better yet, you should probably always use PostMessage();
So all the code that you have seen before is correct, instead use the following:
using System.Runtime.InteropServices;
[DllImport("user32.dll")]
static extern IntPtr PostMessage(int hWnd, int msg, int wParam, int lParam);
PostMessage(-1, WM_SYSCOMMAND, SC_MONITORPOWER, MONITOR_OFF);
At this time of execution and working appropriately (May 11, 2015) I am running
Windows 7 Professional Version 6.1.7601 Service Pack 1 Build 7601
Visual Studio Profesional 2013 Version 12.0.31101.00 Update 4
.NET Framework 4.5.51209
C#
My system is completely up to date.

The answer with the least SLOC:
using System;
using System.Windows.Forms;
using System.Runtime.InteropServices;
static class Program
{
[DllImport("user32.dll")]
static extern IntPtr SendMessage(IntPtr hWnd, uint Msg, int wParam, int lParam);
[STAThread]
static void Main()
{
SendMessage(new Form().Handle, 0x0112, 0xF170, 2);
}
}

For Windows 10 (tested on Pro 64 bits), I was able to turn off the monitor using the SendMessage() technique mentioned in this page.
However, impossible for me to turn the monitor back on: the "mouse move" trick did not work, the SendMessage() technique would turn the screen back on for one second then back off and using PostMessage() did not change anything.
But the trick is in fact really simple, all I had to do was simulate a keypress with SendKeys(). I'm using ALT here because in itself it has no impact on the system but it could be any other key.
SendKeys.SendWait("%");
If you're not using Windows.Forms, sending "ALT" also works using SendInput() but it's longer to implement.

Launch external process associated with a file and send this application to the back

I've seen loads of code to launch an external application via a file, but that's not the problem. To clarify exactly the behaviour I want:
For a given filename, launch the correct process.
If there is no associated process, the proper shell dialog should prompt the user to associate one.
While the application is launched, this application needs to go to the back of the Z-order (or just behind the app that is launching) and STAY THERE.
Step 3 is what I haven't got right. I am launching Photoshop via a psd file, but while the aplash screen is shown, it flashes as my app fights for the focus. Once it starts up properly, all is well, but I don't like the flickering while the flash screen is displayed.
Here is my best attempt so far:
using System;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.Security;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace Romy.Core
{
internal static class Example
{
public const int SW_RESTORE = 9;
private static readonly IntPtr HWND_BOTTOM = new IntPtr(1);
private const uint SWP_NOACTIVATE = 0x0010;
private const uint SWP_NOMOVE = 0x0002;
private const uint SWP_NOSIZE = 0x0001;
public static void SendWindowBack(IntPtr handle)
{
NativeMethods.SetWindowPos(handle, HWND_BOTTOM, 0, 0, 0, 0, SWP_NOSIZE | SWP_NOMOVE | SWP_NOACTIVATE);
}
public static async void ShellExecuteFile(this IWin32Window window, string filename)
{
var p = Process.Start(new ProcessStartInfo()
{
FileName = filename,
Verb = "open",
UseShellExecute = true,
ErrorDialog = true
});
SendWindowBack(window.Handle);
try
{
await Task.Run(async () =>
{
try
{
p.WaitForInputIdle();
IntPtr handle = p.MainWindowHandle;
while (handle == IntPtr.Zero)
{
await Task.Delay(TimeSpan.FromMilliseconds(250D));
handle = p.MainWindowHandle;
}
if (handle != IntPtr.Zero)
{
if (NativeMethods.IsIconic(handle))
NativeMethods.ShowWindowAsync(handle, SW_RESTORE);
if (NativeMethods.SetForegroundWindow(handle))
NativeMethods.SetActiveWindow(handle);
}
}
catch (InvalidOperationException) { }
catch (PlatformNotSupportedException) { }
catch (NotSupportedException) { }
catch (Exception ex) { ex.Log(); }
}).TimeoutAfter(TimeSpan.FromSeconds(3D));
}
catch (TimeoutException) { }
}
[SuppressUnmanagedCodeSecurity]
internal static class NativeMethods
{
[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
internal static extern bool IsIconic(System.IntPtr hWnd);
[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
internal static extern bool SetForegroundWindow(System.IntPtr hWnd);
[DllImport("user32.dll")]
internal static extern bool SetWindowPos(IntPtr hWnd, IntPtr hWndInsertAfter,
int X, int Y, int cx, int cy, uint uFlags);
[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
internal static extern bool ShowWindowAsync(System.IntPtr hWnd, int nCmdShow);
[DllImport("user32.dll")]
internal static extern System.IntPtr SetActiveWindow(System.IntPtr hWnd);
}
}
}

Try removing your call to SendWindowBack and replace SetForegroundWindow with SetWindowLong. This should meet your requierment:
...(or just behind the app that is launching) and STAY THERE..
const int GWL_HWNDPARENT = (-8);
[DllImport("user32.dll", SetLastError = true)]
static extern int SetWindowLong(IntPtr childHandle, int nIndex, IntPtr parentHandle);
if (handle != IntPtr.Zero)
{
if (NativeMethods.IsIconic(handle))
NativeMethods.ShowWindowAsync(handle, SW_RESTORE);
SetWindowLong(handle, GWL_HWNDPARENT, window.Handle)
NativeMethods.SetActiveWindow(handle);
}

How to cancel the exit option in c# [duplicate]

This question already has an answer here:
how can i disable close button of console window in a visual studio console application?
(1 answer)
Closed 9 years ago.
I need to know if there is an option to cancel the exit key in the console application?
I added an image url describing the button that i want to cancel, surrounded with red color.
http://i44.tinypic.com/2dj18d0.jpg
Thanks!

You can do that using a Windows API.
This code do the trick:
using System;
using System.Collections.Generic;
using System.Text;
using System.Runtime.InteropServices;
namespace BlogConsole
{
class API
{
[DllImport("user32.dll")]
static extern bool EnableMenuItem(IntPtr hMenu, uint uIDEnableItem, uint uEnable);
[DllImport("user32.dll")]
static extern IntPtr GetSystemMenu(IntPtr hWnd, bool bRevert);
internal const UInt32 SC_CLOSE = 0xF060;
internal const UInt32 MF_ENABLED = 0x00000000;
internal const UInt32 MF_GRAYED = 0x00000001;
internal const UInt32 MF_DISABLED = 0x00000002;
internal const uint MF_BYCOMMAND = 0x00000000;
public static void EnableCloseButton(IntPtr handle, bool bEnabled)
{
IntPtr hSystemMenu = GetSystemMenu(handle, false);
EnableMenuItem(hSystemMenu, SC_CLOSE, (uint)(MF_ENABLED | (bEnabled ? MF_ENABLED : MF_GRAYED)));
}
}
}
This is the way you call it:
static void Main(string[] args)
{
IntPtr handle = Process.GetCurrentProcess().MainWindowHandle;
API.EnableCloseButton(handle, false);
}

How to programmatically minimize opened window folders

How can I get the list of opened of folders, enumerate through it and minimize each folder programmatically?
At times some opened folders do steal focus from the tool when jumping from one form in the application to another. Preventing this is of high priority for our client. The customers are visually impaired people, so they access the machine only via screen readers. Minimizing other windows (folders) is not at all a problem, in fact a requirement.
I tried this:
foreach (Process p in Process.GetProcessesByName("explorer"))
{
p.StartInfo.WindowStyle = ProcessWindowStyle.Minimized;
}
As expected it did no good.
Update:
From the answers here, I tried this:
delegate bool EnumThreadDelegate(IntPtr hWnd, IntPtr lParam);
[DllImport("user32.dll")]
static extern bool EnumThreadWindows(int dwThreadId, EnumThreadDelegate lpfn, IntPtr lParam);
static IEnumerable<IntPtr> EnumerateProcessWindowHandles(int processID)
{
List<IntPtr> handles = new List<IntPtr>();
EnumThreadDelegate addWindowHandle = delegate(IntPtr hWnd, IntPtr param)
{
handles.Add(hWnd);
return true;
};
foreach (ProcessThread thread in Process.GetProcessById(processID).Threads)
EnumThreadWindows(thread.Id, addWindowHandle, IntPtr.Zero);
return handles;
}
const int SW_MINIMIZED = 6;
[DllImport("user32.dll")]
static extern int ShowWindow(IntPtr hWnd, int nCmdShow);
private void button1_Click(object sender, EventArgs e)
{
foreach (IntPtr handle in EnumerateProcessWindowHandles(Process.GetProcessesByName("explorer")[0].Id))
ShowWindow(handle, SW_MINIMIZED);
}
This creates a whole lot of invisible explorer windows to be suddenly listed in the taksbar out of no where. I am bit noob in dealing with Windows API, so the code itself will actually help.

Please try this (the code is somewhat messy but for the purpose you should be able to go through it ;))
using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using System.Diagnostics;
using System.Text;
using System.Globalization;
namespace WindowsFormsApplication20
{
static class Program
{
[STAThread]
static void Main()
{
foreach (IntPtr handle in EnumerateProcessWindowHandles(Process.GetProcessesByName("explorer")[0].Id))
{
SendMessage(handle, WM_SYSCOMMAND, SC_MINIMIZE, 0);
}
}
[DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]
static extern int GetClassName(IntPtr hWnd, StringBuilder lpClassName, int nMaxCount);
static string GetDaClassName(IntPtr hWnd)
{
int nRet;
StringBuilder ClassName = new StringBuilder(100);
//Get the window class name
nRet = GetClassName(hWnd, ClassName, ClassName.Capacity);
if (nRet != 0)
{
return ClassName.ToString();
}
else
{
return null;
}
}
delegate bool EnumThreadDelegate(IntPtr hWnd, IntPtr lParam);
[DllImport("user32.dll")]
static extern bool EnumThreadWindows(int dwThreadId, EnumThreadDelegate lpfn, IntPtr lParam);
static IEnumerable<IntPtr> EnumerateProcessWindowHandles(int processID)
{
List<IntPtr> handles = new List<IntPtr>();
EnumThreadDelegate addWindowHandle = delegate(IntPtr hWnd, IntPtr param)
{
string className = GetDaClassName(hWnd);
switch (className)
{
case null:
break;
case "ExploreWClass":
handles.Add(hWnd);
break;
case "CabinetWClass":
handles.Add(hWnd);
break;
default:
break;
}
return true;
};
foreach (ProcessThread thread in Process.GetProcessById(processID).Threads)
EnumThreadWindows(thread.Id, addWindowHandle, IntPtr.Zero);
return handles;
}
[DllImport("user32.dll", CharSet = CharSet.Auto)]
static extern IntPtr SendMessage(IntPtr hWnd, UInt32 Msg, int wParam, int lParam);
const int WM_SYSCOMMAND = 274;
const int SC_MINIMIZE = 0xF020;
}
}
Best regards,
Żubrówka

//Create Instance Of Shell Class by referencing COM Library "Microsoft Shell Controls And Automation" -shell32.dll
Shell32.ShellClass objShell = new Shell32.ShellClass();
//Show Desktop
((Shell32.IShellDispatch4)objShell).ToggleDesktop();
Edit: to show your application (Activate or Maximize/Restore) after toggling actually turned out to be quite difficult:
I tried:
Application.DoEvents();
System.Threading.Thread.Sleep(5000);
Even overriding the WndProc didn't manage to capture the event:
private const Int32 WM_SYSCOMMAND = 0x112;
private const Int32 SC_MINIMIZE = 0xf020;
protected override void WndProc(ref Message m)
{
if (m.Msg == WM_SYSCOMMAND)
{
if (m.WParam.ToInt32() == SC_MINIMIZE)
return;
}
base.WndProc(ref m);
}
So I suggest instead of Minimising all other windows, just stick yours on top during the operation, then once your finished turn off Always On Top:
[DllImport("user32.dll")]
static extern bool SetWindowPos(IntPtr hWnd, IntPtr hWndInsertAfter, int X, int Y, int cx, int cy, uint uFlags);
static readonly IntPtr HWND_TOPMOST = new IntPtr(-1);
const UInt32 SWP_NOSIZE = 0x0001;
const UInt32 SWP_NOMOVE = 0x0002;
const UInt32 TOPMOST_FLAGS = SWP_NOMOVE | SWP_NOSIZE;
public static void MakeTopMost (IntPtr hWnd)
{
SetWindowPos(hWnd, HWND_TOPMOST, 0, 0, 0, 0, TOPMOST_FLAGS);
}

There is a less 'hacky' solution than the accepted answer available here: Minimize a folder
It's based on the Shell Objects for Scripting. Sample:
const int SW_SHOWMINNOACTIVE = 7;
[DllImport("user32.dll")]
static extern bool ShowWindow(IntPtr hWnd, int nCmdShow);
static void MinimizeWindow(IntPtr handle)
{
ShowWindow(handle, SW_SHOWMINNOACTIVE);
}
//call it like:
foreach (IWebBrowser2 window in new Shell().Windows())
{
if (window.Name == "Windows Explorer")
MinimizeWindow((IntPtr)window.HWND);
}
The same thing can be achieved using the Internet Explorer Object Model
// add a reference to "Microsoft Internet Controls" COM component
// also add a 'using SHDocVw;'
foreach (IWebBrowser2 window in new ShellWindows())
{
if (window.Name == "Windows Explorer")
MinimizeWindow((IntPtr)window.HWND);
}

If you are willing to use p-invoke you can use EnumThreadWindows to enumerate all windows of a process. Then use ShowWindow to minimize them.

I know this is an old post, but here is a much shorter, simpler way in case people are still looking for a solution:
Using Windows API:
Declare a windows handle: (minimizes the calling executable)
HWND wHandle; //can be any scope - I use it in main
Call the following anywhere (depending on scope of wHandle):
wHandle = GetActiveWindow();
ShowWindow(wHandle, SW_SHOWMINNOACTIVE);

Dynamically changing Mouse speed

Guys, I have a C# Winforms application with a panel inside the form. What I want to do is, whenever the mouse pointer enters this panel, I want to slow the movement speed of the mouse by 50%. Once the pointer moves outside this panel, I want to speed of the mouse to resume normal 100% speed. How can I accomplish this in C#?

This article might help
Here's the code from the article:
using System;
using System.Runtime.InteropServices;
namespace MouseSpeedSwitcher
{
class Program
{
public const UInt32 SPI_SETMOUSESPEED = 0x0071;
[DllImport("User32.dll")]
static extern Boolean SystemParametersInfo(
UInt32 uiAction,
UInt32 uiParam,
UInt32 pvParam,
UInt32 fWinIni);
static void Main(string[] args)
{
SystemParametersInfo(
SPI_SETMOUSESPEED,
0,
uint.Parse(args[0]),
0);
}
}
}

using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;
namespace ConsoleApplication1
{
class Program
{
public const UInt32 SPI_GETMOUSESPEED = 0x0070;
const UInt32 SPIF_UPDATEINIFILE = 0x01;
const UInt32 SPIF_SENDWININICHANGE = 0x02;
[DllImport("User32.dll")]
static extern Boolean SystemParametersInfo(
UInt32 uiAction,
UInt32 uiParam,
IntPtr pvParam,
UInt32 fWinIni);
static unsafe void Main(string[] args)
{
MouseOptions m = new MouseOptions();
MouseOptions.GetDefaults();
int speed;
SystemParametersInfo(SPI_GETMOUSESPEED, 0, new IntPtr(&speed), 0);
Console.WriteLine(speed);
MouseOptions.SetDefaults();
SystemParametersInfo(SPI_GETMOUSESPEED, 0, new IntPtr(&speed), 0);
Console.WriteLine(speed);
Console.ReadLine();
}
public class MouseOptions
{
[DllImport("user32.dll")]
public static extern int SystemParametersInfo( int uAction, int uParam, IntPtr lpvParam, int fuWinIni );
[DllImport("kernel32.dll")]
public static extern int GetLastError();
public const int SPI_GETMOUSESPEED = 112;
public const int SPI_SETMOUSESPEED = 113;
private static int intDefaulSpeed = 10;
private static int intCurrentSpeed;
private static int intNewSpeed;
public static void GetDefaults()
{
intCurrentSpeed = GetMouseSpeed();
}
public static void SetDefaults()
{
if ( intCurrentSpeed == 20 )
{
SetMouseSpeed(intDefaulSpeed);
}
else if ( intCurrentSpeed < 10 )
{
SetMouseSpeed(intDefaulSpeed);
}
}
public static int GetMouseSpeed()
{
int intSpeed = 0;
IntPtr ptr;
ptr = Marshal.AllocCoTaskMem(4);
SystemParametersInfo(SPI_GETMOUSESPEED, 0, ptr, 0);
intSpeed = Marshal.ReadInt32(ptr);
Marshal.FreeCoTaskMem(ptr);
return intSpeed;
}
public static void SetMouseSpeed( int intSpeed )
{
IntPtr ptr = new IntPtr(intSpeed);
int b = SystemParametersInfo(SPI_SETMOUSESPEED, 0, ptr, 0);
if (b == 0)
{
Console.WriteLine("Not able to set speed");
}
else if ( b == 1 )
{
Console.WriteLine("Successfully done");
}
}
}
}
}

As it was not very clear how to use code from the answers, I found more concise solution for changing Mouse speed. Add this code to class where you want to change the speed:
[DllImport("user32.dll", CharSet = CharSet.Auto),]
public static extern int SystemParametersInfo(uint uiAction, uint uiParam, uint pvParam, uint fWinIni);
And then call SystemParametersInfo with required Mouse speed:
//SPEED is an integer value between 0 and 20. 10 is the default.
SystemParametersInfo(113,0,SPEED,0);
Not forget to add using System.Runtime.InteropServices; Credits.