Question about managed and unmanaged codes in VC++.NET

[querry]

Hi all,

I am developing a Windows Form Application in VC++. I am using using Visual Studio 2005. My project requires me to use the Boost Libraries [for more info visit www.boost.org] These boost libraries are unmanaged code, where as my application itself is managed code. I have a seperae set of unmanaged classes doing the bulk of the work. Now I want to use these classes form the managed class of my application.

Let me give a example... Say I have a form and a button on it. I want to call a perticular function form the unmanaged code when the button is clicked. How do I do that? Or say when the button is clicked and if at all, I am able to call the function which is returning, say a array. How do I get the values of the elements in the array populaed into a ListBox?

Please help me...
I am new to VC++...
Thanks

[misza]

Hi,

I also started using managed c++ not so long ago, so maybe someone more experienced could help you better;

but for a good start;) :

- you can use unmanaged objects in your managed class, even as members, e.g.

public ref class Example
{
  public:
     UnmanagedClass* m_member; // here it's important to use a pointer, otherwise the code won't compile
};

- as for using return values from unmanaged, check marshaling:
http://msdn2.microsoft .com/en-us/library/system.runtime. interopservices .marshal.aspx

...and examples you asked:

Say I have a form and a button on it. I want to call a perticular function form the unmanaged code when the button is clicked. How do I do that?

private: System::Void button1_Click(/* args */)
{
   UnmanClass unman();
   unman.someFunction();
   (...)
}

Or say when the button is clicked and if at all, I am able to call the function which is returning, say a array. How do I get the values of the elements in the array populaed into a ListBox?

(...)
int[] returned = unman.getArray(length);
lstBox->Items->Clear(); // assuming you have a lstBox member of type ListBox^
for(int i=0; i< length; i++)
{
  lstBox->Items->Add(returned[i]); // for simple types (like int) - you don't have to convert them from unmanaged to managed, for other check the marshaling
}
(...)

in the second example I didn't use std::string or char* (which is more logical for a listbox;) - to see how to convert string to System::String and back, check here:
http://www.thescripts. com/forum/thread281603.ht ml
or here:
http://support.microso ft.com/kb/311259

and last but not least, in case of c++/cli syntax issues, check here, quite a good tutorial:
http://www.functionx.c om/cppcli/index.htm

I hope I was at least a little helpful;)

M.

[querry]

Thanks misza,

I will try that out. Thanks a lot.