Managed C++/CLI

Re: How can i include CTime

3-Jun-09 2:49

i want to use in my code CTime!!!
any one can help

Garth J Lancaster3-Jun-09 2:58

Garth J Lancaster

3-Jun-09 2:58

how about

1) try some patience & manners

2) use :-

#include <ctime>

[edit] this is asuming you dont mean the MFC CTime class - if you mean that you'll have to add the MFC includes etc if you havnt build an MFC project [/edit]

'g'

Re: How can i include CTime

George L. Jackson3-Jun-09 7:45

Re: How can i include CTime

3-Jun-09 7:45

If you are trying to convert a time_t to a DateTime in C++/CLI see: http://www.codeproject.com/Messages/3066386/Re-Convert-to-datetime-problem.aspx[^]

"We make a living by what we get, we make a life by what we give." --Winston Churchill

Mark Salsbery3-Jun-09 11:48

Mark Salsbery

3-Jun-09 11:48

#include <atltime.h>

COleDateTime has a better range

#include <ATLComTime.h>

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Convert to datetime problem

wael_r3-Jun-09 2:33

3-Jun-09 2:33

i'm using window forms application and i'm facing a problem with a variable date_time that hold
a long value 1243930978
I need to convert this number to datetime
Note : when i declare the variable as "CTime sss" it give error undeclared identifier "sss"
any one can help?

wael_r3-Jun-09 3:25

3-Jun-09 3:25

Can any one help

Re: Convert to datetime problem [modified]

Luc Pattyn3-Jun-09 4:34

Luc Pattyn

3-Jun-09 4:34

Hi,

this forum is about C++/CLI, that's the managed C++ dialect, part of .NET
it has a very nice DateTime class with some constructors, and useful methods such as Parse() and TryParse().
AFAIK there is no CTime in its universe.

Are you in the right forum? for plain C/C++ and MFC use the appropriate forum!

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

The quality and detail of your question reflects on the effectiveness of the help you are likely to get.
Show formatted code inside PRE tags, and give clear symptoms when describing a problem.

George L. Jackson3-Jun-09 6:54

3-Jun-09 6:54

The value, 1243930978, is calculated from the number of seconds from 1/1/1970. To convert to a DateTime, you must account for this offset:

DateTime time_offset(1970, 1, 1);
DateTime time_converted = time_offset.AddSeconds(1243930978);

"We make a living by what we get, we make a life by what we give." --Winston Churchill

modified on Wednesday, June 3, 2009 4:36 PM

wael_r3-Jun-09 20:20

Re: Convert to datetime problem [modified]

3-Jun-09 20:20

Thank you very much, i want you to know that i spend 2 days on this.
and now you gave me the right answer Thankkkkkkkkk youuuuuuuuuuuuuuuuuu.
i tried it works it gave me 3 hours difference and i handle it by adding 10800 sec
to the number. but why it gave me difference 3 hours?

George L. Jackson4-Jun-09 1:53

4-Jun-09 1:53

If the value was created on computer in local time EST, and it was converted on a computer in local time PST, you will have a 3 hour difference. You should use coordinated universal time (UTC) and adjust the time according to the local time of the computer. .NET has DateTime.UtcNow and DateTime.ToUniversalTime and C/C++ has gmtime.

"We make a living by what we get, we make a life by what we give." --Winston Churchill

modified on Thursday, June 4, 2009 8:02 AM

wael_r4-Jun-09 2:07

4-Jun-09 2:07

Please can you give me exactly how to use this function in the code?

George L. Jackson4-Jun-09 2:48

4-Jun-09 2:48

Which function you need an example for? If you are using .NET 3.5, you can use the DateTimeOffset structure: .[^][^]. Examples for DateTime.ToUniversalTime method: http://msdn.microsoft.com/en-us/library/system.datetime.touniversaltime.aspx[^]. DateTime.UtcNow works like DateTime.Now: http://msdn.microsoft.com/en-us/library/system.datetime.utcnow.aspx[^]. gmtime: http://msdn.microsoft.com/en-us/library/0z9czt0w.aspx[^]. And, _mkgmtime: http://msdn.microsoft.com/en-us/library/2093ets1.aspx[^].

"We make a living by what we get, we make a life by what we give." --Winston Churchill

wael_r4-Jun-09 23:01

Using a DLL containing MFC functions in a Managed C++ app (Help please) [modified]

4-Jun-09 23:01

Thanks it works fine. with UtcNow

James19762-Jun-09 21:42

Re: Using a DLL containing MFC functions in a Managed C++ app (Help please)

2-Jun-09 21:42

Hello,

I am experiencing some link errors and would like to ask your help please.

I have a managed C++ workspace, which contains the main app (.exe) and a DLL project that it links to called Editor.dll.

The DLL contains MFC classes for the doc/view classes (e.g. CEditorDoc, CEditorView, etc).

The DLL builds fine, but the main application .exe (managed C++) produces link errors when these DLL classes are used
within it, as demonstrated below:

Linking...
WindowsApplication.obj : error LNK2028: unresolved token "public: static struct CRuntimeClass 
* __stdcall CEditorDoc::GetThisClass(void)" (?GetThisClass@CEditorDoc@@$$FSGPAUCRuntimeClass@@XZ) referenced 
in function "int __thiscall CWindowsApplication::InitInstance(void)"

(Please note the header files are included in the main app file where they are used too).

The link errors all seem to be related to a "GetThisClass()" function which i think seems to have trouble being
exported out of the DLL (it is a member of base class MFC). All other functions seem fine. I also have tried
using a .def file but it doesnt seem to help.

Any help would be greatly appreciated. Thanks!

modified on Wednesday, June 3, 2009 8:34 AM

Mark Salsbery3-Jun-09 11:51

Mark Salsbery

3-Jun-09 11:51

James1976 wrote:
a DLL project that it links to called Editor.dll.

Links to how? Did you link to the impost library (Editor.lib)?

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Re: Using a DLL containing MFC functions in a Managed C++ app (Help please)

James19763-Jun-09 23:08

Re: Using a DLL containing MFC functions in a Managed C++ app (Help please)

3-Jun-09 23:08

Thanks for your reply.

I couldnt link the .lib (Editor.lib) as the .lib file is only generated if the DLL contains any exports, which it doesnt currently.

I cant export the function that has the link error (the GetThisClass() function) as its not in my code. Its in the MFC base-class and i cant override it in order to place a "declspec(export)" in front of it.

Also i cant export the entire class since it contains managed C++ code and so cannot be exported (only a class that does not contain managed code can be exported it seems).

Any further suggestions would be appreciated? Thanks.

led mike4-Jun-09 4:28

led mike

4-Jun-09 4:28

James1976 wrote:
I couldnt link the .lib (Editor.lib) as the .lib file is only generated if the DLL contains any exports, which it doesnt currently.

Then you have nothing to link to.

James1976 wrote:
I cant export the function that has the link error (the GetThisClass() function) as its not in my code. Its in the MFC base-class and i cant override it in order to place a "declspec(export)" in front of it.

Then you create your own function that you can export and it calls the MFC function.

James1976 wrote:
(only a class that does not contain managed code can be exported it seems).

That is not true. We use a DLL that I authored that is a mixed mode DLL that exports a native C++ class. That class is used in a native Win32 application. The native classes you export cannot use any managed types as parameters because then they would not be a native interface. However they can use managed objects in the implementation.

James1976 wrote:
Any further suggestions would be appreciated?

See here[^]

Re: Using a DLL containing MFC functions in a Managed C++ app (Help please)

Mark Salsbery4-Jun-09 4:52

Mark Salsbery

4-Jun-09 4:52

Gracias!

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Re: Using a DLL containing MFC functions in a Managed C++ app (Help please)

led mike4-Jun-09 7:30

led mike

4-Jun-09 7:30

Tomorrows is FRIDAY! Jig | [Dance]

Re: Using a DLL containing MFC functions in a Managed C++ app (Help please)

James19764-Jun-09 5:01

Re: Using a DLL containing MFC functions in a Managed C++ app (Help please)

4-Jun-09 5:01

Hi Mike, thanks for your reply.

led mike wrote:
Then you create your own function that you can export and it calls the MFC function.

Even if i add my own function there will still be a compilation error due to the base-class function. I dont think this will work as the base-class function is still directly called by base-class code (that is, the GetThisClass() function is called by the IMPLEMENT_DYNAMIC macro in MFC). I cannot modify MFC to call my own newly added function.

led mike wrote:
That is not true. We use a DLL that I authored that is a mixed mode DLL that exports a native C++ class. That class is used in a native Win32 application. The native classes you export cannot use any managed types as parameters because then they would not be a native interface. However they can use managed objects in the implementation

When i tried to place the "declspec(export)" declaration in front of any class that contains managed C++, it generated a compiler error. I wonder why it worked okay for you, perhaps i dont have something correct in my code? I'll double-check this, thanks.

led mike wrote:
See here[^]

Thanks for your link. I have already tried most of these, including using a .def file (which seemed to accept the .def file but still displayed the linkage errors) and using the declspec(export) for the class as mentioned above.

I have a small sample project that i could email to demonstrate, if yourself or anyone else wouldnt mind taking a look? Any help would be greatly appreciated.

Thanks,
James

led mike4-Jun-09 5:17

led mike

4-Jun-09 5:17

James1976 wrote:
Thanks for your link. I have already tried most of these

Have you seen this[^]?

Re: Using a DLL containing MFC functions in a Managed C++ app (Help please)

James19764-Jun-09 5:21