system.py 文件源码

def _major_version(self):
        """
        int: Indicates the major portion of the installed version of NI-
            DAQmx, such as 7 for version 7.0.
        """
        val = ctypes.c_uint()

        cfunc = lib_importer.windll.DAQmxGetSysNIDAQMajorVersion
        if cfunc.argtypes is None:
            with cfunc.arglock:
                if cfunc.argtypes is None:
                    cfunc.argtypes = [
                        ctypes.POINTER(ctypes.c_uint)]

        error_code = cfunc(
            ctypes.byref(val))
        check_for_error(error_code)

        return val.value