C# Signature:

[DllImport("Kernel32.dll", SetLastError=true)]
static extern IntPtr OpenEvent(uint dwDesiredAccess, bool bInheritHandle, string lpName);

User-Defined Types:

None.

Notes:

None.

Tips & Tricks:

Tip 1: Use OpenEvent to open named event and attach it to AutoResetEvent class:

  AutoResetEvent are= new AutoResetEvent(false);
  are.Close();
  GC.ReRegisterForFinalize(are);
  are.Handle= handle; // handle from OpenEvent

Sample Code:

  // taken from header files
  const uint STANDARD_RIGHTS_REQUIRED    = 0x000F0000;
  const uint SYNCHRONIZE             = 0x00100000;
  const uint EVENT_ALL_ACCESS        = (STANDARD_RIGHTS_REQUIRED|SYNCHRONIZE|0x3);
  const uint EVENT_MODIFY_STATE        = 0x0002 ;
  const long ERROR_FILE_NOT_FOUND        = 2L;

    /// <summary>
    /// Security enumeration from:
    /// http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dllproc/base/synchronization_object_security_and_access_rights.asp
    /// </summary>
    [Flags]
    public enum SyncObjectAccess : uint
    {
        DELETE                    = 0x00010000,
        READ_CONTROL            = 0x00020000,
        WRITE_DAC                = 0x00040000,
        WRITE_OWNER                = 0x00080000,
        SYNCHRONIZE                = 0x00100000,
        EVENT_ALL_ACCESS        = 0x001F0003,
        EVENT_MODIFY_STATE        = 0x00000002,
        MUTEX_ALL_ACCESS        = 0x001F0001,
        MUTEX_MODIFY_STATE        = 0x00000001,
        SEMAPHORE_ALL_ACCESS    = 0x001F0003,
        SEMAPHORE_MODIFY_STATE    = 0x00000002,
        TIMER_ALL_ACCESS        = 0x001F0003,
        TIMER_MODIFY_STATE        = 0x00000002,
        TIMER_QUERY_STATE        = 0x00000001
    }

  // open event with error handling
  IntPtr handle= OpenEvent(EVENT_ALL_ACCESS | EVENT_MODIFY_STATE, false, name);
  int le= Marshal.GetLastWin32Error();
  if ((handle==IntPtr.Zero) && (le!=0) && (le!=ERROR_FILE_NOT_FOUND))
    throw new ApplicationException(string.Format("Error in pinvoked CreateEvent: {0}", le));

Alternative Managed API:

CreateEvent also opens an existing (named) event...

EventWaitHandle.OpenExisting already encapsulates this API: http://msdn.microsoft.com/en-us/library/433b98s3(v=vs.80).aspx

The EventWaitHandleRights enum is also already defined for you.

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