Invoke .NET from MFC(COM object - ActiveX)

Hi there...
A couple of days ago I wanted to use a .NET assembly from a MFC application. You can see other post where I explain how to make an interface in .NET and expose it to COM.

In this post I want to show you how to call a method from that assembly that has a byte[] parameter. and how to get a parameter from a COM object. As you can see(if you've made that .tbl file and imported in C++), the byte[] parameter from .NET is exposed as a SAFEARRAY*.
The trick is to create a SAFEARRAY* like this:
BYTE* myBuffer = ... ; // the length of the buffer is len
SAFEARRAYBOUND sabdBounds[1] = { {len, 0} };
LPSAFEARRAY psa = SafeArrayCreate(VT_UI1, 1, sabdBounds);
memcpy(psa->pvData, myBuffer, len);
//call the method from .NET assembly

To call a method or get a property from a COM object, you can use the InvokeHelper method:

//get signature BSTR string
VARIANT vtResult;
this->GetDlgItem(IDC_MyActiveXID)->InvokeHelper(propertyId, DISPATCH_PROPERTYGET
DISPATCH_METHOD, VT_VARIANT, (void*)&vtResult, NULL);

After this call, you should check on vtResult.vt to see the return type.

Have fun!

Exposing .NET Components to COM

Looking on MSDN website you'll find this:
http://msdn.microsoft.com/en-us/library/zsfww439.aspx
So as you can see, you can't expose static components to COM.

C# code:
namespace ClassLibrary1{
[Guid("4322F88E95-DD27-4ae6-B6DE-054440FC70AA")]
[InterfaceType (ComInterfaceType.InterfaceIsIDispatch)]
[ComVisible(true)]
public interface _Class1
{
[DispId(1)]
int Add(int i);
}

[Guid("13FE123D-4D34-495F-AB4D-909BBB463EEA")]
[ClassInterface(ClassInterfaceType.None)]
[ProgId("ClassLibrary1.Class1")]
[ComVisible(true)]
[ComDefaultInterfaceAttribute(typeof(_Class1))]
public class Class1 : _Class1
{
public int Add(int i)
{
return i + 10;
}
}
}


C++ code:
#include "stdafx.h"
//the location must point to the tlb file
#import "D:\\ClassLibrary1\\bin\\Debug\\ClassLibrary1.tlb"
int _tmain(int argc, _TCHAR* argv[])
{
ClassLibrary1::_Class1 *com_ptr;
CoInitialize(NULL);
ClassLibrary1::_Class1Ptr p(__uuidof(ClassLibrary1::Class1));
com_ptr = p;
long a = com_ptr->Add(1);
CoUninitialize();
return 0;
}

To make this work, you have to Register the .NET library to COM from Properties-Build tab and run the command : regasm ClassLibrary1 /tbl:ClassLibrary1.tlb

To deploy this, you'll have to gacutil the assembly.
gacutil /i ClassLibrary1.dll but first you'll have to strong-name sign it.

WPF 3D View

Hello...

A little while ago, I tried Xceed datagrid view... and I saw there a 3D view... You can check it out on their website. A simillar application is on Apple iPhone.

So, I started to make a WPF control simillar to that list.

The control can be found at : www.codeplex.com/3dView

Have fun!