_com_ptr_t::CreateInstance, HRESULT = ERROR_CANNOT_FIND_WND_CLASS
I'm facing a problem with getting a COM interface loaded.
I'll explain the context a little :
i have a CredentialProvider (running at winlogon so) which does a loadlibrary + getProcAddress on a dll. This dll, in each of its functions, load the COM interface this way :
_ConnectionPtr con;
hr = con.CreateInstance(__uuidof(Connection));
if(FAILED(hr)
_com_error err(hr);
LPCTSTR errMsg = err.ErrorMessage();
Log("hr = %s", errMsg);
CoInitializeEx(NULL, COINIT_MULTITHREADED);
hr = con.CreateInstance(__uuidof(Connection));
And it works fine.
However, after entering the userSession, a windows service finally loadlibrary/getProcAddress this same dll.
And when it tries to CreateInstance on the __uuidof(Connection), it fails with error "ERROR_CANNOT_FIND_WND_CLASS - Cannot find window class".
How should i interpret this error ? Actually, should i ?
Does someone have an idea of why it could fail with windows service while it succeeds few seconds before with the credentialProvider ?
Feel free to ask if any details is missing.
Thank you for any solution/clue/tip.
c++ com windows-services ado
edited Nov 22 '18 at 16:34
Alexander
3791315
asked Nov 14 '18 at 13:57
SillimonSillimon
43
|
show 9 more comments
I'm facing a problem with getting a COM interface loaded.
I'll explain the context a little :
i have a CredentialProvider (running at winlogon so) which does a loadlibrary + getProcAddress on a dll. This dll, in each of its functions, load the COM interface this way :
_ConnectionPtr con;
hr = con.CreateInstance(__uuidof(Connection));
if(FAILED(hr)
_com_error err(hr);
LPCTSTR errMsg = err.ErrorMessage();
Log("hr = %s", errMsg);
CoInitializeEx(NULL, COINIT_MULTITHREADED);
hr = con.CreateInstance(__uuidof(Connection));
And it works fine.
However, after entering the userSession, a windows service finally loadlibrary/getProcAddress this same dll.
And when it tries to CreateInstance on the __uuidof(Connection), it fails with error "ERROR_CANNOT_FIND_WND_CLASS - Cannot find window class".
How should i interpret this error ? Actually, should i ?
Does someone have an idea of why it could fail with windows service while it succeeds few seconds before with the credentialProvider ?
Feel free to ask if any details is missing.
Thank you for any solution/clue/tip.
c++ com windows-services ado
edited Nov 22 '18 at 16:34
Alexander
3791315
asked Nov 14 '18 at 13:57
SillimonSillimon
43
In my opinion, it looks like the issue most likely lies in implementationConnection, where the initialization of it fails with such error code, which gets, simply, returned to the user (you).
– Algirdas Preidžius
Nov 14 '18 at 14:10
I do not implement Connection, it comes from msado15.dll which, i think, is quite safe. Also, the credentialProvider uses the same implementation, right ?
– Sillimon
Nov 14 '18 at 14:25
I am not familiar with the components, that you are using. I am merely stating my opinion, regarding the possible source of the error, based on information provided.
– Algirdas Preidžius
Nov 14 '18 at 14:35
1
Does your service callCoInitializeorCoInitializeEx?
– Alexander
Nov 16 '18 at 8:52
1
You're a fucking genius. CoInitializeEx was failing in Service. Still don't know why Initializing through dll did not work though...
– Sillimon
Nov 16 '18 at 14:11
|
show 9 more comments
I'm facing a problem with getting a COM interface loaded.
I'll explain the context a little :
i have a CredentialProvider (running at winlogon so) which does a loadlibrary + getProcAddress on a dll. This dll, in each of its functions, load the COM interface this way :
_ConnectionPtr con;
hr = con.CreateInstance(__uuidof(Connection));
if(FAILED(hr)
_com_error err(hr);
LPCTSTR errMsg = err.ErrorMessage();
Log("hr = %s", errMsg);
CoInitializeEx(NULL, COINIT_MULTITHREADED);
hr = con.CreateInstance(__uuidof(Connection));
And it works fine.
However, after entering the userSession, a windows service finally loadlibrary/getProcAddress this same dll.
And when it tries to CreateInstance on the __uuidof(Connection), it fails with error "ERROR_CANNOT_FIND_WND_CLASS - Cannot find window class".
How should i interpret this error ? Actually, should i ?
Does someone have an idea of why it could fail with windows service while it succeeds few seconds before with the credentialProvider ?
Feel free to ask if any details is missing.
Thank you for any solution/clue/tip.
c++ com windows-services ado
edited Nov 22 '18 at 16:34
Alexander
3791315
asked Nov 14 '18 at 13:57
SillimonSillimon
43
I'm facing a problem with getting a COM interface loaded.
I'll explain the context a little :
i have a CredentialProvider (running at winlogon so) which does a loadlibrary + getProcAddress on a dll. This dll, in each of its functions, load the COM interface this way :
_ConnectionPtr con;
hr = con.CreateInstance(__uuidof(Connection));
if(FAILED(hr)
_com_error err(hr);
LPCTSTR errMsg = err.ErrorMessage();
Log("hr = %s", errMsg);
CoInitializeEx(NULL, COINIT_MULTITHREADED);
hr = con.CreateInstance(__uuidof(Connection));
And it works fine.
However, after entering the userSession, a windows service finally loadlibrary/getProcAddress this same dll.
And when it tries to CreateInstance on the __uuidof(Connection), it fails with error "ERROR_CANNOT_FIND_WND_CLASS - Cannot find window class".
How should i interpret this error ? Actually, should i ?
Does someone have an idea of why it could fail with windows service while it succeeds few seconds before with the credentialProvider ?
Feel free to ask if any details is missing.
Thank you for any solution/clue/tip.
c++ com windows-services ado
c++ com windows-services ado
edited Nov 22 '18 at 16:34
Alexander
3791315
asked Nov 14 '18 at 13:57
SillimonSillimon
43
edited Nov 22 '18 at 16:34
Alexander
3791315
asked Nov 14 '18 at 13:57
SillimonSillimon
43
edited Nov 22 '18 at 16:34
Alexander
3791315
edited Nov 22 '18 at 16:34
Alexander
3791315
edited Nov 22 '18 at 16:34
Alexander
3791315
3791315
asked Nov 14 '18 at 13:57
SillimonSillimon
43
asked Nov 14 '18 at 13:57
SillimonSillimon
43
asked Nov 14 '18 at 13:57
SillimonSillimon
43
43
In my opinion, it looks like the issue most likely lies in implementationConnection, where the initialization of it fails with such error code, which gets, simply, returned to the user (you).
– Algirdas Preidžius
Nov 14 '18 at 14:10
I do not implement Connection, it comes from msado15.dll which, i think, is quite safe. Also, the credentialProvider uses the same implementation, right ?
– Sillimon
Nov 14 '18 at 14:25
I am not familiar with the components, that you are using. I am merely stating my opinion, regarding the possible source of the error, based on information provided.
– Algirdas Preidžius
Nov 14 '18 at 14:35
1
Does your service callCoInitializeorCoInitializeEx?
– Alexander
Nov 16 '18 at 8:52
1
You're a fucking genius. CoInitializeEx was failing in Service. Still don't know why Initializing through dll did not work though...
– Sillimon
Nov 16 '18 at 14:11
|
show 9 more comments
In my opinion, it looks like the issue most likely lies in implementationConnection, where the initialization of it fails with such error code, which gets, simply, returned to the user (you).
– Algirdas Preidžius
Nov 14 '18 at 14:10
I do not implement Connection, it comes from msado15.dll which, i think, is quite safe. Also, the credentialProvider uses the same implementation, right ?
– Sillimon
Nov 14 '18 at 14:25
I am not familiar with the components, that you are using. I am merely stating my opinion, regarding the possible source of the error, based on information provided.
– Algirdas Preidžius
Nov 14 '18 at 14:35
1
Does your service callCoInitializeorCoInitializeEx?
– Alexander
Nov 16 '18 at 8:52
1
You're a fucking genius. CoInitializeEx was failing in Service. Still don't know why Initializing through dll did not work though...
– Sillimon
Nov 16 '18 at 14:11
In my opinion, it looks like the issue most likely lies in implementation
Connection, where the initialization of it fails with such error code, which gets, simply, returned to the user (you).– Algirdas Preidžius
Nov 14 '18 at 14:10
In my opinion, it looks like the issue most likely lies in implementation
Connection, where the initialization of it fails with such error code, which gets, simply, returned to the user (you).– Algirdas Preidžius
Nov 14 '18 at 14:10
I do not implement Connection, it comes from msado15.dll which, i think, is quite safe. Also, the credentialProvider uses the same implementation, right ?
– Sillimon
Nov 14 '18 at 14:25
I do not implement Connection, it comes from msado15.dll which, i think, is quite safe. Also, the credentialProvider uses the same implementation, right ?
– Sillimon
Nov 14 '18 at 14:25
I am not familiar with the components, that you are using. I am merely stating my opinion, regarding the possible source of the error, based on information provided.
– Algirdas Preidžius
Nov 14 '18 at 14:35
I am not familiar with the components, that you are using. I am merely stating my opinion, regarding the possible source of the error, based on information provided.
– Algirdas Preidžius
Nov 14 '18 at 14:35
1
1
Does your service call
CoInitialize or CoInitializeEx?– Alexander
Nov 16 '18 at 8:52
Does your service call
CoInitialize or CoInitializeEx?– Alexander
Nov 16 '18 at 8:52
1
1
You're a fucking genius. CoInitializeEx was failing in Service. Still don't know why Initializing through dll did not work though...
– Sillimon
Nov 16 '18 at 14:11
You're a fucking genius. CoInitializeEx was failing in Service. Still don't know why Initializing through dll did not work though...
– Sillimon
Nov 16 '18 at 14:11
|
show 9 more comments
0
active
oldest
votes
Your Answer
StackExchange.ifUsing("editor", function ()
StackExchange.using("externalEditor", function ()
StackExchange.using("snippets", function ()
StackExchange.snippets.init();
);
);
, "code-snippets");
StackExchange.ready(function()
var channelOptions =
tags: "".split(" "),
id: "1"
;
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function()
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled)
StackExchange.using("snippets", function()
createEditor();
);
else
createEditor();
);
function createEditor()
StackExchange.prepareEditor(
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader:
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
,
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
);
);
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53301932%2fcom-ptr-tcreateinstance-hresult-error-cannot-find-wnd-class%23new-answer', 'question_page');
);
Post as a guest
Required, but never shown
0
active
oldest
votes
0
active
oldest
votes
active
oldest
votes
active
oldest
votes
Thanks for contributing an answer to Stack Overflow!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53301932%2fcom-ptr-tcreateinstance-hresult-error-cannot-find-wnd-class%23new-answer', 'question_page');
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
In my opinion, it looks like the issue most likely lies in implementation
Connection, where the initialization of it fails with such error code, which gets, simply, returned to the user (you).– Algirdas Preidžius
Nov 14 '18 at 14:10
I do not implement Connection, it comes from msado15.dll which, i think, is quite safe. Also, the credentialProvider uses the same implementation, right ?
– Sillimon
Nov 14 '18 at 14:25
I am not familiar with the components, that you are using. I am merely stating my opinion, regarding the possible source of the error, based on information provided.
– Algirdas Preidžius
Nov 14 '18 at 14:35
1
Does your service call
CoInitializeorCoInitializeEx?– Alexander
Nov 16 '18 at 8:52
1
You're a fucking genius. CoInitializeEx was failing in Service. Still don't know why Initializing through dll did not work though...
– Sillimon
Nov 16 '18 at 14:11