Rahul said:
Hello,
Is it possible (by code) to set a timer and "force" the computer to
wake up from hibernation/standby/sleep mode (either at specific
time... or after specific interval) through C# code?
Please let me know about any possible solutions/ideas you may have.
Thanks,
Rahul
Nothing in the framework, so you'll have to "PInvoke" a bit.
The API's you need to call are CreateWaitableTimer and SetWaitableTimer.
Following is a complete (Q&D) sample that illustrates how you can set a
system to be awoken from sleep/hibernate using above Win32 API's.
Note that here I'm setting a relative wakeup time of 300000000 nSecs.
That means that the computer will wake-up (supposing he's asleep or
hibernating) within 30 seconds after setting the timer.
Consult the MSDN docs for details on SetWaitableTimer and it's arguments.
using System;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using System.Threading;
namespace Willys
{
class Program
{
[DllImport("kernel32.dll")]
public static extern IntPtr CreateWaitableTimer(IntPtr
lpTimerAttributes,
bool bManualReset, string lpTimerName);
[DllImport("kernel32.dll")]
public static extern bool SetWaitableTimer(IntPtr hTimer, [In] ref long
pDueTime, int lPeriod, IntPtr pfnCompletionRoutine, IntPtr
lpArgToCompletionRoutine, bool fResume);
[DllImport("kernel32", SetLastError = true, ExactSpelling = true)]
public static extern Int32 WaitForSingleObject(IntPtr handle, uint
milliseconds);
static void Main()
{
SetWaitForWakeUpTime();
}
static IntPtr handle;
static void SetWaitForWakeUpTime()
{
long duetime = -300000000; // negative value, so a RELATIVE
due time
handle = CreateWaitableTimer(IntPtr.Zero, true,
"MyWaitabletimer");
SetWaitableTimer(handle, ref duetime, 0, IntPtr.Zero,
IntPtr.Zero, true);
long duetime = -300000000;
Console.WriteLine("{0:x}",duetime);
handle = CreateWaitableTimer(IntPtr.Zero, true,
"MyWaitabletimer");
SetWaitableTimer(handle, ref duetime, 0, IntPtr.Zero,
IntPtr.Zero, true);
uint INFINITE = 0xFFFFFFFF;
int ret = WaitForSingleObject(handle, INFINITE);
MessageBox.Show("Wake up call");
}
}
Willy.