Solved

From managed Object* to unmanaged IUnknown

Posted on 2004-04-09
10
740 Views
Last Modified: 2013-12-03
I would like to use Extended MAPI in my C# programm, read a String-Property from a Message.

For this purpose I write a managed/unmanaged C++ DLL.

I have an Object* from mail.MAPIOBJECT which should be of the type IUnknown according to Microsoft documentation.
I need an LPMAPIPROP for HrGetOneProp(LPMAPIPROP pmp, int ulPropTag, LPVOID lppPro) which can be (I'm not sure, but I found it on a webpage) a pointer to a IUnknown.
But what are the lines between?

I tried:
     static String* GetStringProperty(Object* MAPIObject, int PropertyNumber) {
       String* Val;          
       char* bufVal;
       IntPtr pUnk = Marshal::GetIUnknownForObject(MAPIObject);
       LPMAPIPROP pMsgMAPI = (LPMAPIPROP)pUnk.ToPointer();
       if (pMsgMAPI!=0) {
         int hRes = HrGetOneProp(pMsgMAPI, PropertyNumber, (LPBYTE*)&bufVal);
         if (bufVal != 0) {
           if (hRes == 0) {
             Val = Marshal::PtrToStringUni(bufVal);
           }
           MAPIFreeBuffer(bufVal);
         }
       }
       return Val;
     }

pUnk gets a Value but pMsgMAPI/IUnknown says undefined.

0
Comment
Question by:BillyX
  • 5
  • 3
10 Comments
 
LVL 8

Expert Comment

by:RomanPetrenko
ID: 10826295
Try this code:

IUnknown *pUnk = (IUnknown*)Marshal::GetIUnknownForObject(MAPIObject).ToPointer();
LPMAPIPROP pMsgMAPI;
pUnk->QueryInterface(&pMsgMAPI); // or pUnk->QueryInterface(<GUID_OF_MAPIPROP>, (void**)&pMsgMAPI);
pUnk->Release();
0
 

Author Comment

by:BillyX
ID: 10829106
I tried:

EXTERN_C const GUID DECLSPEC_SELECTANY IMAPIProp = { 0x00020303, 0, 0, {  0xC0, 0, 0, 0, 0, 0, 0, 0x46 } };
EXTERN_C const GUID DECLSPEC_SELECTANY IMAPIMessage = { 0x00020307, 0, 0, {  0xC0, 0, 0, 0, 0, 0, 0, 0x46 } };

Microsoft::Office::Interop::Outlook::MailItem * mi = ... ;
Object* MAPIObject;
MAPIObject = mi->MAPIOBJECT;

IUnknown* pUnk = (IUnknown*)Marshal::GetIUnknownForObject(MAPIObject).ToPointer();
LPMAPIPROP pMsgMAPI;
int res = pUnk->QueryInterface(IMAPIProp, (void**)&pMsgMAPI);
pUnk->Release();

res gets the value -2147467259 which is MAPI_E_CALL_FAILED

I also tried to convert mi the same way to IMAPIMessage and that returned the same error :-(
0
 
LVL 8

Expert Comment

by:RomanPetrenko
ID: 10830749
Don't you run this code in windows service or ASP page or MTS or schedulers?
look here:
INFO: Outlook Object Model Unsuitable to Run in a Windows Service
http://support.microsoft.com/default.aspx?scid=http://support.microsoft.com:80/support/kb/articles/q237/9/13.asp&NoWebContent=1
0
 

Author Comment

by:BillyX
ID: 10832376
No, it dosen't.
Also
       String* Val;          
       Val = mi->get_To();
works correctly. It is only the cast of mi->MAPIOBJECT or mi that fails...
0
Do You Know the 4 Main Threat Actor Types?

Do you know the main threat actor types? Most attackers fall into one of four categories, each with their own favored tactics, techniques, and procedures.

 
LVL 8

Expert Comment

by:RomanPetrenko
ID: 10832831
And if you write
Microsoft::Office::Interop::Outlook::MailItem * mi = ... ;
HrGetOneProp(mi->MAPIOBJECT, PropertyNumber, (LPBYTE*)&bufVal);
Do you get compile time error?
0
 

Author Comment

by:BillyX
ID: 10834345
error C2440: 'type cast' : cannot convert from 'System::Object __gc *' to 'LPMAPIPROP'
0
 

Author Comment

by:BillyX
ID: 10873411
I have found a solution myself:

http://www.mapilab.com/dev/mapiprop/

This is a library which allows accessing of the mapi-properties directly from .NET. It is also with sourcecode so I should be able compare how they solve this.
0
 

Author Comment

by:BillyX
ID: 10873636
@Mod Please close question and refund points!
0
 

Accepted Solution

by:
modulo earned 0 total points
ID: 11249525
PAQed, with points refunded (250)

modulo
Community Support Moderator
0

Featured Post

Enabling OSINT in Activity Based Intelligence

Activity based intelligence (ABI) requires access to all available sources of data. Recorded Future allows analysts to observe structured data on the open, deep, and dark web.

Join & Write a Comment

For those of you who don't follow the news, or just happen to live under rocks, Microsoft Research released a beta SDK (http://www.microsoft.com/en-us/download/details.aspx?id=27876) for the Xbox 360 Kinect. If you don't know what a Kinect is (http:…
Real-time is more about the business, not the technology. In day-to-day life, to make real-time decisions like buying or investing, business needs the latest information(e.g. Gold Rate/Stock Rate). Unlike traditional days, you need not wait for a fe…
Excel styles will make formatting consistent and let you apply and change formatting faster. In this tutorial, you'll learn how to use Excel's built-in styles, how to modify styles, and how to create your own. You'll also learn how to use your custo…
Access reports are powerful and flexible. Learn how to create a query and then a grouped report using the wizard. Modify the report design after the wizard is done to make it look better. There will be another video to explain how to put the final p…

707 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

17 Experts available now in Live!

Get 1:1 Help Now