Need help calling a proprietary C DLL from Python

[Chris Mellon]

On Thu, Mar 20, 2008 at 3:42 PM, Craig <craigm3604 at gmail.com> wrote:
>
> On Mar 20, 2:38 pm, Craig <craigm3... at gmail.com> wrote:
>  > On Mar 20, 2:29 pm, sturlamolden <sturlamol... at yahoo.no> wrote:
>  >
>  > > On 20 Mar, 19:09, Craig <craigm3... at gmail.com> wrote:
>  >
>  > > The culprit i here:
>  >
>  > > > Before - X = 0, CacheSize = 0, OpenMode = 3, vHandle = 0
>  >
>  > > This binds these names to Python ints, but byref expects C types.
>  >
>  > > Also observe that CacheSize and OpenMode should be c_short.
>  >
>  > I changed CacheSize and OpenMode to c_short, and commented out that
>  > line producing the "Before" message, and the output is the same.
>  >
>  > Further "tinkering" revealed that it is the byref on the fName and pw
>  > that are causing the error.
>  >
>  > The entire problem appears to be around the production of a BSTR and
>  > the passing of pointers (byref) to the BSTR.
>
>
>  Can anyone shed some light on how to work with BSTR's?

Since you didn't tell ctypes about the function signature, it assumes
it returns int and gives you a python int. Provide a function
signature (c_void_p should work for BSTR) for both functions and you
should have an easier time of it.

>
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