[RESOLVED] Why is CreateEvent Not Functioning Correctly

When I run the code below, the return value from WaitForSingleObjects is 0, despite the fact that I specified in CreateEvent for the initial state to be non-signaled. The code functions correctly if I uncomment the ResetEvent command (resulting in a return value of WAIT_TIMEOUT). The handle from CreateEvent is valid, but is not properly setting the initial state. Does anyone know why this might be happening?

VB Code:

Public Declare Function ResetEvent Lib "kernel32" (ByVal hEvent As Long) As Long
Public Declare Function WaitForSingleObject Lib "kernel32" (ByVal hHandle As Long, ByVal dwMilliseconds As Long) As Long
Public Declare Function CreateEvent Lib "kernel32" Alias "CreateEventA" (ByVal lpEventAttributes As Long, ByVal bManualReset As Long, ByVal bInitialState As Long, ByVal lpName As String) As Long
 
Private Sub test() 
    
    Dim hTest As Long
    Dim lngRetVal As Long
 
    hTest = CreateEvent(ByVal 0&, True, False, ByVal 0&)
    'ResetEvent (hTest)
    lngRetVal = WaitForSingleObject(hTest, 0)
    
    If (lngRetVal = 0) Then
         'Code Enters Here
    Else
         'Does Not Enter Here
    End If
 
End Sub

I run your code and it always returns WAIT_TIMEOUT, with or without ResetEvent

Jcis: Are you running VB6 in Windows XP SP2? So far I have only found one other instance on the web where someone had the same question on another forum (that went unanswered). He too was running it in Windows XP SP2.

I have tested both in the IDE and compiled form. Neither one is working for me. But as best as I can tell (and further confirmed by your success) there is nothing wrong with the code.

Thank you for your input.

Quote:

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Originally Posted by Joey_k29

Jcis: Are you running VB6 in Windows XP SP2?

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Yes, tested and works fine in 2 computers, both with Windows XP SP2 + VB6.

Very odd. I don't know how to explain it. I tested other code where I created an event and reset it in the same function. In a later function, I called WaitForSingleObject with it, and it failed to wait indicating the event was set despite the fact that there was no code to set the event.

The problem I encountered is ByVal 0& is not correct as the last parameter in create event. Doing so results in a named event. vbNullString properly results in an unnamed event and solves my issue.

Thank you for your help.