Managed C++/CLI

Re: Loading and Freeing Assemblies

28-Mar-07 14:07

As far as I know, ordinary .NET languages do not provide a means to deterministically unload an assembly once it has been loaded by the CLR.

Does this hold true also for C++/CLI?

I would like to be able to unload assemblies for the purpose of auto-updating them while leaving the app's main assembly running. Is this possible?

While I'm at it, am I allowed to use LoadLibrary() and FreeLibrary() with a mixed-mode assembly, or must I use Assembly.Load() ?

-- modified at 20:24 Wednesday 28th March, 2007

--------------------------------

"All that is necessary for the forces of evil to win in the world is for enough good men to do nothing" -- Edmund Burke

George L. Jackson29-Mar-07 11:39

George L. Jackson

29-Mar-07 11:39

LoadLibrary and FreeLibrary is used in unmanaged code. I haven't used it with C++/CLI but I believe it can be used to load native DLLs. If you want to load managed assemblies, you use Assembly.Load. However, if you want to have the freedom of loading and unloading assemblies I believe you must create an AppDomain. I have not verified this, so you need to do your own research.

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

Re: Loading and Freeing Assemblies

Richard Andrew x6429-Mar-07 11:47

Re: Loading and Freeing Assemblies

29-Mar-07 11:47

Thanks, George. Info on C++/CLI seems a little hard to come by, so I guess I'll have to do some experimentation.

--------------------------------

"All that is necessary for the forces of evil to win in the world is for enough good men to do nothing" -- Edmund Burke

Nish Nishant1-Apr-07 3:20

Nish Nishant

1-Apr-07 3:20

Richie308 wrote:
Thanks, George. Info on C++/CLI seems a little hard to come by, so I guess I'll have to do some experimentation.

What George suggested is the only way to do what you want. You cannot directly unload an assembly without unloading all appdomains that have loaded that assembly. And if your primary appdomain has loaded the assembly, this means you cannot unload the assembly at all without exiting the application.

The way to do this is to have a secondary appdomain, load the temporary assemblies there, and when you are done just unload the secondary appdomain - this will unload all assemblies used by that appdomain that are not otherwise in use.

By the way I wouldn't call this C++/CLI specific information - this would fall under general .NET in my opinion Smile | :)

Regards,
Nish

Nish’s thoughts on MFC, C++/CLI and .NET (my blog)
C++/CLI in Action (*E-Book is out, Print version April 6th*)

What constitutes a mixed type

Richard Andrew x6427-Mar-07 10:03

Re: What constitutes a mixed type [modified]

27-Mar-07 10:03

I am studying Nish's book C++/CLI in Action. In it, we learn that mixed types are not supported, but yet the book shows a wrapper for the Desktop API's that contains functions that mix native types with managed types.

For instance, some of the functions use an HDESK type alongside managed types.

So my question is, what exactly is not supported when they say "mixed types are not supported?"

--------------------------------

"All that is necessary for the forces of evil to win in the world is for enough good men to do nothing" -- Edmund Burke

George L. Jackson27-Mar-07 11:11

George L. Jackson

27-Mar-07 11:11

You need to reread "4.3 Using mixed types". He said the C++/CLI compiler does not directly support mixed types. A "ref class" with a member field that is a native class is considered a mixed type. However, a pointer to a native class can be a field of a "ref class":

It is not supported here:

class NativeFoo
{
  // ...
};

ref class ManagedFoo
{
  NativeFoo m_foo;
};

But it is here:

ref class ManagedFoo
{
  NativeFoo* m_foo;

  ~ManagedFoo()
  {
    this->!ManagedFoo();
  }

  !ManagedFoo()
  {
    delete m_foo;
  }

};

However, using "NativeFoo* m_foo" does not lead to safe and reliable code since the developer is responsible for managing its resource. See http://msdn2.microsoft.com/en-us/library/aa730837(vs.80).aspx[^] for more information.

-- modified at 18:04 Tuesday 27th March, 2007

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

Re: What constitutes a mixed type

Richard Andrew x6427-Mar-07 12:05

Generated C++ from designer causes exception in CodeDOM [modified]

27-Mar-07 12:05

Thanks for you post. I will study that document. Smile | :)

--------------------------------

"All that is necessary for the forces of evil to win in the world is for enough good men to do nothing" -- Edmund Burke

std::string.insert

Andy H27-Mar-07 6:08

Andy H

27-Mar-07 6:08

Can some kind soul tell me how to insert a char imediately after every occurance of another char in a string.

Re: std::string.insert

Nish Nishant27-Mar-07 6:14

Nish Nishant

27-Mar-07 6:14

Andy H wrote:
Can some kind soul tell me how to insert a char imediately after every occurance of another char in a string.

Please ask in the Visual C++ forum. This one's for C++/CLI related queries.

Regards,
Nish

Nish’s thoughts on MFC, C++/CLI and .NET (my blog)
C++/CLI in Action (*E-Book is out, Print version April 6th*)

SE_GEEK26-Mar-07 11:33

SE_GEEK

26-Mar-07 11:33

I am experiencing a rather irritating problem in a Managed C++ application I have written. I have a form that is using a custom control that I wrote in C#. The code runs correctly, however whenever the designer generates the C++ code in the ".h" file for the form it prefixes the type of my control with a "::". This causes an exception in the CodeDOM parser when I then try to use the design view of the form.

The custom control is called ImageDisplay, and it is within a namespace of ImageDisplay.

Here is the offending line of code:

this->imageDisplayFront = (gcnew ::ImageDisplay::ImageDisplay());

If I change the line to:

this->imageDisplayFront = (gcnew ImageDisplay::ImageDisplay());

Then all is well in the universe until the next time I make a change in the designer that generates code. Is there a trick I can do to keep whatever is generating this code from adding the extra "::"?

I am running Visual Studio 2005 with service pack 1.

-- modified at 9:03 Tuesday 27th March, 2007

Truly wise men don't play leap frog with Unicorns.

Run time code generation

Bhupinder Sodhi25-Mar-07 23:14

25-Mar-07 23:14

Hii guys,
i need your help in understanding the concept "Rum time code generation" .
I want to make a program which should insert some code in other running program without any re-compilation and re-link. i know this is possible. But i dont know to implement it as i am beginner to programming.

Thanks
Bhupinder Sodhi

Mark Salsbery26-Mar-07 10:59

Mark Salsbery

26-Mar-07 10:59

Some info here[^].

"If you can dodge a wrench, you can dodge a ball."

Bhupinder Sodhi26-Mar-07 17:03

26-Mar-07 17:03

i searched google already many times..even i found many projects related to this..but it did nt help me!!

Christian Graus26-Mar-07 17:05

Christian Graus

26-Mar-07 17:05

Bhupinder Sodhi wrote:
as i am beginner to programming.

Walk before you run, or you will always crawl.

Christian Graus - Microsoft MVP - C++
Metal Musings - Rex and my new metal blog
"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )

Bhupinder Sodhi26-Mar-07 22:42

26-Mar-07 22:42

You are right !!
but these sayings cant change my determination to solve my problem!!
please guys help me...i need to know the answer not your thoughts and sayings..

Christian Graus27-Mar-07 2:38

Christian Graus

27-Mar-07 2:38

I think what we're saying is, if you're a beginner, you should learn the language of your choice before jumping into the most advanced topics.

Why C++/CLI ? It's the least supported .NET language, and the most complex one.

Bhupinder Sodhi27-Mar-07 2:47