try ctypes load onnxruntime.dll, CreateEnv get null return

[ssuurrffaaccee]

run below code on window10 with onnxruntime-win-x64-1.18.1

import ctypes as cts 
API_VRESION=18
VoidPtr  = cts.c_void_p
CharPtr  = cts.c_char_p
WCharPtr = cts.c_wchar_p # for win32
Int32    = cts.c_int32
UInt32   = cts.c_uint32
Size     = cts.c_size_t
Ref      = cts.POINTER 
ByRef    = cts.byref

OrtLoggingLevel = Int32
OrtErrorCode = Int32

class OrtEnv(cts.Structure):
    pass 
OrtEnvPtr = cts.POINTER(OrtEnv)

class OrtStatus(cts.Structure):
    pass
OrtStatusPtr = cts.POINTER(OrtStatus)

class OrtApi(cts.Structure):
        _fields_ =[("CreateEnv",cts.CFUNCTYPE(OrtStatusPtr,OrtLoggingLevel,CharPtr,Ref(OrtEnvPtr))),
                   ("GetErrorCode",   cts.CFUNCTYPE(OrtErrorCode, OrtStatusPtr)),
                   ("GetErrorMessage",cts.CFUNCTYPE(CharPtr, OrtStatusPtr)),
                   ]
class OrtApiBase(cts.Structure):
    _fields_ = [("GetApi",           cts.CFUNCTYPE(cts.POINTER(OrtApi),cts.c_uint)),
                ("GetVersionString", cts.CFUNCTYPE(cts.c_char_p))]
    
ORT_DLL = cts.windll.LoadLibrary("./onnxruntime.dll")
ORT_DLL.OrtGetApiBase.argtypes=[]
ORT_DLL.OrtGetApiBase.restype = cts.POINTER(OrtApiBase)
ORT_API_BASE = ORT_DLL.OrtGetApiBase().contents
G_ORT_API = ORT_API_BASE.GetApi(API_VRESION).contents

def showStatus(status):
    if not status:
        return 
    error_code = G_ORT_API.GetErrorCode(status)
    error_message = G_ORT_API.GetErrorMessage(status)
    print("er: ",error_code," msg: ",error_message)

env = OrtEnvPtr()
status = G_ORT_API.CreateEnv(0,b"test",ByRef(env))
showStatus(status)
print(env[0])

i got:

er:  0  msg:  b'test'
Traceback (most recent call last):
  File "C:\Users\bc\Downloads\test\ort\ortx.py", line 48, in <module>
    print(env[0])
          ~~~^^^
ValueError: NULL pointer access

anyone know why? please help, tanks

[ssuurrffaaccee]

I solved the problem. :(
In C, OrtApi is a struct, so the order of members in a fields is meaningful, should be consistent with the order of the struct members in C and cannot be skipped