Delay system sleep mode

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Hi am using below code to awake system back from sleep mode..but its not working am not able to figure out the problem can anyone help? Thanks.

C#

#region prevent screensaver, display dimming and automatically sleeping
       POWER_REQUEST_CONTEXT _PowerRequestContext;
       IntPtr _PowerRequest; //HANDLE

       // Availability Request Functions
       [DllImport("kernel32.dll")]
       static extern IntPtr PowerCreateRequest(ref POWER_REQUEST_CONTEXT Context);

       [DllImport("kernel32.dll")]
       static extern bool PowerSetRequest(IntPtr PowerRequestHandle, PowerRequestType RequestType);

       [DllImport("kernel32.dll")]
       static extern bool PowerClearRequest(IntPtr PowerRequestHandle, PowerRequestType RequestType);

       [DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true, ExactSpelling = true)]
       internal static extern int CloseHandle(IntPtr hObject);



       // Availablity Request Enumerations and Constants
       enum PowerRequestType
       {
           PowerRequestDisplayRequired = 0,
           PowerRequestSystemRequired,
           PowerRequestAwayModeRequired,
           PowerRequestMaximum

       }

       const int POWER_REQUEST_CONTEXT_VERSION = 0;
       const int POWER_REQUEST_CONTEXT_SIMPLE_STRING = 0x1;
       const int POWER_REQUEST_CONTEXT_DETAILED_STRING = 0x2;

       // Availablity Request Structures
       // Note:  Windows defines the POWER_REQUEST_CONTEXT structure with an
       // internal union of SimpleReasonString and Detailed information.
       // To avoid runtime interop issues, this version of
       // POWER_REQUEST_CONTEXT only supports SimpleReasonString.
       // To use the detailed information,
       // define the PowerCreateRequest function with the first
       // parameter of type POWER_REQUEST_CONTEXT_DETAILED.
       [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
       public struct POWER_REQUEST_CONTEXT
       {
           public UInt32 Version;
           public UInt32 Flags;
           [MarshalAs(UnmanagedType.LPWStr)]
           public string
               SimpleReasonString;
       }

       [StructLayout(LayoutKind.Sequential)]
       public struct PowerRequestContextDetailedInformation
       {
           public IntPtr LocalizedReasonModule;
           public UInt32 LocalizedReasonId;
           public UInt32 ReasonStringCount;
           [MarshalAs(UnmanagedType.LPWStr)]
           public string[] ReasonStrings;
       }

       [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
       public struct POWER_REQUEST_CONTEXT_DETAILED
       {
           public UInt32 Version;
           public UInt32 Flags;
           public PowerRequestContextDetailedInformation DetailedInformation;
       }
       #endregion


       /// <summary>
       /// Prevent screensaver, display dimming and power saving. This function wraps PInvokes on Win32 API.
       /// </summary>
       /// <param name="enableConstantDisplayAndPower">True to get a constant display and power - False to clear the settings</param>
       public void EnableConstantDisplayAndPower(bool enableConstantDisplayAndPower)
       {
           if (enableConstantDisplayAndPower)
           {
               //// Set up the diagnostic string
               _PowerRequestContext.Version = POWER_REQUEST_CONTEXT_VERSION;
               _PowerRequestContext.Flags = POWER_REQUEST_CONTEXT_SIMPLE_STRING;
               _PowerRequestContext.SimpleReasonString = "Continuous measurement"; // your reason for changing the power settings;

               //// Create the request, get a handle
               _PowerRequest = PowerCreateRequest(ref _PowerRequestContext);

               // Set the request
               PowerSetRequest(_PowerRequest, PowerRequestType.PowerRequestSystemRequired);
               PowerSetRequest(_PowerRequest, PowerRequestType.PowerRequestDisplayRequired);




           }
           else
           {
               // Clear the request
               PowerClearRequest(_PowerRequest, PowerRequestType.PowerRequestSystemRequired);
               PowerClearRequest(_PowerRequest, PowerRequestType.PowerRequestDisplayRequired);

               CloseHandle(_PowerRequest);
           }
       }

Posted 28-Oct-14 2:05am

Gayatri Kadam

Updated 4-Apr-20 8:05am

Herman<T>.Instance

v2

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Comments

Dave Kreskowiak 28-Oct-14 9:46am

Your code is ignoring the return values from those function calls. You might want to look at those and see what the return values mean.

Gayatri Kadam 29-Oct-14 2:44am

it still goes into sleep mode even if I handle that..

Dave Kreskowiak 29-Oct-14 8:25am

<SMACK!> WHAT ARE THE RETURN VALUES?!?!?!

Mehdi Gholam 28-Oct-14 10:04am

Your code will not run when the computer is in sleep mode!

Gayatri Kadam 29-Oct-14 2:44am

Actually its not working in sleep mode..

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Bill Duffy · Answer 1 · 2020-04-04T08:06:00

var powerRequest = IntPtr.Zero;
var powerSuccess = false;

try
{
    Debug.WriteLine("Suspending system sleep");

    // Set up the diagnostic string
    POWER_REQUEST_CONTEXT powerRequestContext;
    powerRequestContext.Version = POWER_REQUEST_CONTEXT_VERSION;
    powerRequestContext.Flags   = POWER_REQUEST_CONTEXT_SIMPLE_STRING;
    powerRequestContext.SimpleReasonString = "Compacting database"; 

    powerRequest = Imports.PowerCreateRequest(ref powerRequestContext);
    if (powerRequest == IntPtr.Zero)
    {
        var error = Marshal.GetLastWin32Error();
        Debug.WriteLine($"{nameof(Imports.PowerCreateRequest)} failed, error={error}");
    }
    else if (! (powerSuccess = Imports.PowerSetRequest(powerRequest, PowerRequestType.PowerRequestSystemRequired)))
    {
        var error = Marshal.GetLastWin32Error();
        Debug.WriteLine($"{nameof(Imports.PowerSetRequest)} failed, error={error}");
    }

    // do something that you don't want interrupted
}
finally
{
    if (powerRequest != IntPtr.Zero)
    {
        Debug.WriteLine("Resuming system sleep");

        // Clear the request
        if (powerSuccess)
        {
            if (! Imports.PowerClearRequest(powerRequest, PowerRequestType.PowerRequestSystemRequired))
            {
                var error = Marshal.GetLastWin32Error();
                Debug.WriteLine($"{nameof(Imports.PowerClearRequest)} failed, error={error}");
            }
        }

        if (! Imports.CloseHandle(powerRequest))
        {
            var error = Marshal.GetLastWin32Error();
            Debug.WriteLine($"{nameof(Imports.CloseHandle)} failed, error={error}");
        }
    }
}