Get the date-time of last windows shutdown event using .NET
Is there a way to find out when the system was last shutdown?
I know there's a way to find out last boot up time using the LastBootUpTime property in Win32_OperatingSystem namespace using WMI.
Is there anything similar to find out last shutdown time?
Thanks.
(everything here is 100% courtesy of JDunkerley's earlier answer)
The solution is above, but the approach of going from a byte
array to DateTime
can be achieved with fewer statements using the BitConverter
.The following six lines of code do the same and give the correct DateTime
from the registry:
public static DateTime GetLastSystemShutdown()
{
string sKey = @"System\CurrentControlSet\Control\Windows";
Microsoft.Win32.RegistryKey key = Microsoft.Win32.Registry.LocalMachine.OpenSubKey(sKey);
string sValueName = "ShutdownTime";
byte[] val = (byte[]) key.GetValue(sValueName);
long valueAsLong = BitConverter.ToInt64(val, 0);
return DateTime.FromFileTime(valueAsLong);
}
Assuming Windows is shutdown smoothly. It stores it in the registry:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Windows\ShutdownTime
It is stored as an array of bytes but is a FILETIME.
While there may be a better way, I have used this before and think it works:
public static DateTime GetLastSystemShutdown()
{
string sKey = @"System\CurrentControlSet\Control\Windows";
Microsoft.Win32.RegistryKey key = Microsoft.Win32.Registry.LocalMachine.OpenSubKey(sKey);
string sValueName = "ShutdownTime";
object val = key.GetValue(sValueName);
DateTime output = DateTime.MinValue;
if (val is byte[] && ((byte[])val).Length == 8)
{
byte[] bytes = (byte[])val;
System.Runtime.InteropServices.ComTypes.FILETIME ft = new System.Runtime.InteropServices.ComTypes.FILETIME();
int valLow = bytes[0] + 256 * (bytes[1] + 256 * (bytes[2] + 256 * bytes[3]));
int valTwo = bytes[4] + 256 * (bytes[5] + 256 * (bytes[6] + 256 * bytes[7]));
ft.dwLowDateTime = valLow;
ft.dwHighDateTime = valTwo;
DateTime UTC = DateTime.FromFileTimeUtc((((long) ft.dwHighDateTime) << 32) + ft.dwLowDateTime);
TimeZoneInfo lcl = TimeZoneInfo.Local;
TimeZoneInfo utc = TimeZoneInfo.Utc;
output = TimeZoneInfo.ConvertTime(UTC, utc, lcl);
}
return output;
}
Last Restart time can be found using this piece of code
static void Main(string[] args)
{
TimeSpan t = TimeSpan.FromMilliseconds(System.Environment.TickCount);
Console.WriteLine( DateTime.Now.Subtract(t));
}