用python做一个windows平台的工具，纯python缺乏接口，因此想用ctypes模块调用Windows API来实现，碰到了下列问题：
用python封装Windows 中的SystemTimeToFileTime，调用过程中提示参数不对。
Windows API 原型

BOOL WINAPI SystemTimeToFileTime(
__in const SYSTEMTIME* lpSystemTime,
__out LPFILETIME lpFileTime
);

python 封装代码：

from ctypes import *
from ctypes.wintyps import *
#封装 SYSTEMTIME 类型
class SYSTEMTIME(Structure):
fields = [("Year", WORD),
("Month", WORD),
("DayOfWeek", WORD),
("Day", WORD),
("Hour", WORD),
("Min", WORD),
("Sec", WORD),
("MillSec", WORD)]

FILETIME

class FILETIME(Structure):
fields = [("dwLowDateTime", DWORD),
("dwHighDateTime", DWORD)]

封装SystemTimeToFileTime

proto_systm2filetm = WINFUNCTYPE(BOOL, POINTER(SYSTEMTIME), POINTER(FILETIME))
paramflags = (1, "systime", None), (2, "filetime", None)
SystemTimeToFileTime = proto_systm2filetm(("SystemTimeToFileTime", windll.kernel32),
paramflags)
#测试
atime = FILETIME()
atime.dwLowDateTime = 0
atime.dwHighDateTime = 100
systm = SYSTEMTIME()
systm.Year = 2015
systm.Month = 1
systm.Day = 5
systm.DayOfWeek = 1
systm.Hour = 1
systm.Min = 17
systm.Sec = 0

print SystemTimeToFileTime(systime = pointer(systm), filetime=pointer(atime))
print "error:%d" % GetLastError()

#结果：
提示 print SystemTimeToFileTime(systime = pointer(systm), filetime=pointer(atime)）
TypeError: call takes exactly 1 arguments (2 given)
疑问：SystemTimeToFileTime明明声明了2个参数，为啥提示只接受一个参数？
尝试修改，将paramflags该成：
paramflags = (1, "systime", None), (1, "filetime", None)
这下没有提示参数个数不对了，但是函数执行返回FALSE, GetLastError == 87(参数不正确）。
请各位帮忙把把脉，API中的 IN, OUT参数，用ctypes应该如何包装？ 使用时如何传实参？
万分感谢！

evntrace不需要关心，重点是调用方式

 class TestEventClass(event.EventClass):
      _fields_ = [('TestString', field.String),
                  ('TestInt32', field.Int32),
                  ('TestInt64', field.Int64)]

    time_s = int(time.time())
    date_time = datetime.datetime.utcfromtimestamp(time_s)
    sys_time = evntrace.SYSTEMTIME(
        date_time.year, date_time.month, 0, date_time.day,
        date_time.hour, date_time.minute, date_time.second,
        date_time.microsecond / 1000)
    file_time = ctypes.wintypes.FILETIME()
    ctypes.windll.kernel32.SystemTimeToFileTime(ctypes.byref(sys_time),
                                                ctypes.byref(file_time))
    time_stamp = file_time.dwHighDateTime
    time_stamp <<= 32
    time_stamp |= file_time.dwLowDateTime