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Wheven I put this API call as private or public:
Private Declare Function CreateFile Lib "kernel32" Alias "CreateFileA" (ByVal lpFileName As String, ByVal dwDesiredAccess As Long, ByVal dwShareMode As Long, lpSecurityAttributes As SECURITY_ATTRIBUTES, ByVal dwCreationDisposition As Long, ByVal dwFlagsAndAttributes As Long, ByVal hTemplateFile As Long) As Long
it gives me an error message saying:
User-Defined type not defined
What is rong with that and how do I fix that?
Change this:
... lpSecurityAttributes As SECURITY_ATTRIBUTES ...
To this:
... ByVal lpSecurityAttributes As Long ...
And when calling the function, just pass zero here. :rolleyes:
Not to be picky, but lpSecurityAttributes really ought to be:
ByVal lpSecurityAttributes As Any
When calling the function, pass Null.
The cases where it matters whether this is a Long set to zero or an Any set to Null are rare, but I've run into cases where a Long zero won't work (especially in win2k)
I had trouble with it on Win2K, to get it to work (it was declared as any), I passed "ByVal 0&". (which probably is the same as Null)
I think CLng(0) would also have worked.
No way.. MSDN says that if you don't want this variable, pass NULL.Quote:
Originally posted by DaveAMS
Not to be picky, but lpSecurityAttributes really ought to be:
ByVal lpSecurityAttributes As Any
When calling the function, pass Null.
MSDN's NULL is different from VB's Null.
When you pass NULL in C++, it passes a pointer whose value is equal to zero (a null pointer).
When you pass Null in VB, it passes a pointer to a valid Variant whose vt member is VT_NULL. :rolleyes: Since the API would think that this is actually a SECURITY_ATTRIBUTES pointer, it would fail.