python调用dll报 violation readint 0x00000000

dll 接口 business_handle（char *,char *） 接收2个指针入参
代码如下：
def business_handle(self,inputData,outputData):

inputData=ctypes.create_string_buffer(inputData)

business_handle = self._libc.BUSINESS_HANDLE
business_handle.argtypes=[ctypes.POINTER(ctypes.c_char),ctypes.POINTER(ctypes.c_char)]
business_handle.restype=ctypes.c_int
business_handle(inputData,outputData)

下断点调试下，你传过去的指针是0，无效的指针。