Hello,
I have a problem with calling Callback function with Python. I have a
DLL file.
Below is a description in documentation.
FUNCTION Callback
Arguments: Callback ID integer read-only, immediate value
CBackProc address read-only, immediate value
Returns: status
The Callback routine registers the callback routine for
notification of a link state change.
The callback procedure provided by the application must
accept one
parameter:
the address of the structure containing the
data.
CallbackID An integer identifying the callback routine being
provided to the API. Can be one of 1 or 2.
CBackProc The address of the callback procedure that the API
will
execute.
This procedure must accept one parameter, of type
LinkStateStruct,
passed by reference.
LinkStateStruct read-only, by reference
OldState: byte
NewState byte
The routine will return one of the following error codes:
1 - The callback address was successfully registered by the API.
2 - The API has not been initialised.
3 - The CallbackID value was not recognised as a valid link
state
callback.
Here is my little code in Python:
from ctypes import *
class LinkStateStruct(Structure):
_fields_ = [("OldState", c_byte),
("NewState", c_byte)]
demoapi=windll.LoadLibrary("D:\\DEMO.dll")
#DECLARE CALLBACK FUNCTION
g_HLSC = CFUNCTYPE(c_int, POINTER(LinkStateStruct))
def py_g_HLSC(x):
print "CALLBACK__py_g_HLSC_FIRED->", x
return 0
g__HLSC = g_HLSC(py_g_HLSC)
status=demoapi.Callback(1,g__HLSC)
print "Status=",status
My result is:
Status= 1
But Callback function is not executed. If think that i call g__HLSC
witohout paramter that in document "The callback procedure
provided by the application must accept one parameter: the address of
the structure containing the data.". I don't now how to do.
Please help.
Best regards,
Gregory
--
http://mail.python.org/mailman/listinfo/python-list
