PInvokeStackImbalance when Openprocess

[sebastiannielsen]

I always get the error PInvokeStackImbalance when im trying to call OpenProcess in my VB 2005 application
I have declared Openprocess as following:

Private Declare Function OpenProcess lib "kernel32.dll" (ByVal dwDesiredAccess as long, ByVal bInheritHandle as boolean, ByVal dwProcessId as long) as long

Im using it in this way:
(ExitPid is a "long" return value from the Shell function earlier in the program)

dim hh as long
hh = OpenProcess(1, false, ExitPid)
TerminateProcess(hh, 0)
CloseHandle(hh)

 

[LazyMe]

VB 2005, as in VB.NET?

API longs are 32 bit, .NET longs are 64 bit, this will create problems on the stack. Maybe you've got things mixed up somewhere....

Greetings,
Rick

 

[sebastiannielsen]

How i do to create a 32 bit long in .NET?

 

[HyperEngineer]

Maybe your process statement should be

  hh = OpenProcess(PROCESS_ALL_ACCESS, 0, ExitPid)

I would think that the long API and the long .NET would be resolved by VB.


HyperEngineer
If it ain't broke, it probably needs improvement.

 

[sebastiannielsen]

im using the value for the constant PROCESS_TERMINATE which evaluates to "1".

But if that was the wrong, the function would only return a zero value (function failed), not crash application and return the error PInvokeStackImbalance.

 

[LazyMe]

VB.NET does not automatically resolve the long API and the long .NET. This not not so strange a behaviour, after all: isn't the declare you have to make just for that; telling .NET /VB6 what kind of parameters to expect/send?

So what happens: You declare your OpenProcess() as receiving parameters of type long. .NET will use 64 bits for those parameters and the windows library expects them to be 32 bits; hence your stack gets corrupted there, hence the error....

Change your declares from long to integer/b] and see if this works.

Greetings,
Rick

 

[chiph]

Or System.UInt32 if you need an unsigned 32-bit integer.

Chip H.


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