All Questions
Tagged with marshalling com
153 questions
0
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0
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53
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Connect to Running Program via COM - Marshal.GetIUnknownForObject
I am using a software package that offers an "extension" package, largely undocumented, that allows for creation of extensions that allow automation within the program. It's a COM interface ...
- 1,004
0
votes
0
answers
80
views
Actual address of COM object in C#
I have a COM object for which I am trying to get the actual underlying address of, so I can get the address of the vtable. I need this to be a valid numerical address because I need to be able to add ...
- 386
1
vote
1
answer
61
views
Prevent the CLR from freeing memory of a marshalled double char pointer?
I am building a Visual Studio 2022 extension in C# and am currently playing around with the VS API. I am trying to call IVsObjectList2.GetText(), which is a COM interface. However, VS is crashing ...
- 6,103
0
votes
0
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99
views
Typesafe COM component with late binding in dotnet
I have some libraries in x32 that I need to call from x64 process. Googling around, I found the best way to do this is using COM components. I created 3 projects in c#:
WinForms project that is X64
...
- 2,248
0
votes
1
answer
81
views
Double hop marshaling in COM
Consider the following.
Process A is a COM client. It creates an object in process B
The object has a method that returns an interface pointer
The implementation in B creates an object in process C ...
- 61.2k
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0
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222
views
Why do CoMarshalInterface and CoUnmarshalInterface need REFIID?
I am a noob regarding COM. In the project that I am currently working we use CoMarshalInterface and CoUnmarshalInterface with REFIID of IDispatch for all the COM object/proxy instances because they ...
- 330
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1
answer
432
views
Marshalling a System.IO.Stream object in c# COM interface
I have a function in my c# COM interface which returns a System.IO.Stream object:
Stream GetFile();
I intend to use this COM interface within unmanaged c++ code, and call this function from there, ...
- 13
1
vote
1
answer
104
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Does COM marshaling work with objects created using CComCoClass::CreateInstance?
Sorry if this is a dumb question, but I was wondering if the COM pointer-marshaling functions will work with objects created using ATL's CComCoClass::CreateInstance. According to the docs, that ...
user15284017
2
votes
1
answer
270
views
Passing a c# array of object to COM interface method
I should pass a pointer of object array to a COM interface with the following IDL and C++ definitions:
C++ code:
UpdateItem( LONG lID, LONG lNumOfFields, FieldIdEnum* pFields, VARIANT* pvValues )
IDL:...
- 19
-1
votes
1
answer
478
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How do I implement an interface from COM in C#
[NOT A DUPLICATE, I've searched for solutions for days and had performed a lot of tests only to find nothing really helps. That's why I registered stackoverflow and posted this.]
[SITUATION]
I am ...
- 11
2
votes
1
answer
165
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"Pure" dispinterface marshaling
Update 2021-04-20: The code presented here is for illustration purposes only. As pointed out by Simon Mourier, for marshaling in-process of such a simple class there is no need for all the TLB ...
1
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0
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170
views
How to marshal C# type to LPWSTR *
I have a native C++ project which has a struct that looks like this:
struct COMStringArray
{
long lSize;
LPWSTR * array;
};
Which uses a com object written in C#, so I need ...
- 593
2
votes
0
answers
148
views
How to avoid expensive array marshalling between VBA and C#?
I'm exporting this C# method through COM:
public interface IMatrixMath {
void AddScaledRange3D(ref double[,,] acc, [In] ref double[,,] vals, double scale);
// ...
}
Then I call it with large ...
- 5,809
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0
answers
248
views
How to solve: At least one of the arguments for '' cannot be marshaled by the runtime marshaler
I have a COM object written in C++ and a C# application using this ActiveX control.
The C++ code is compiling fine, without any warnings.
The C# application is generating several warnings like in the ...
- 3,264
4
votes
3
answers
2k
views
How to serialize a VARIANT or BSTR?
I am trying to figure out some COM marshalling features. Eventually, I want to persist a deeply nested variant array to file but I am trying first with a simple string. I realise these APIs are ...
- 8,220
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2
answers
471
views
How to access C++ COM Object in C# Background worker?
I am developing a common c# COM component (dll) which can be consumed by any COM client. As part of this I m exposing a outgoing interface called ICallback.The client which is using my dll will ...
- 903
3
votes
1
answer
87
views
How to get structured list values from unmanaged c++ code to c#?
I'm writing "ICS/VCS" file parser in win32 c++.
After deserialization from a file, I am storing event data inside a list of event struct.
Now I want to access that structured list in c#.
For that,...
- 307
1
vote
1
answer
184
views
COM interface c# marshalling array of arrays
I have a COM server written in C++ that should interface with a client written in C#.
The C++ COM server exports interface functions to a structure that holds an array of structures with an array ...
3
votes
1
answer
206
views
Pass .NET SecureString to COM Interop
How do you manually marshal a BSTR from .NET to COM?
I am trying to pass a secret stored in a SecureString from my .NET application to a method on a COM object. I want to avoid converting the ...
- 4,958
1
vote
1
answer
343
views
String Array property in COM Class and set it from VBA
I am recently working with one type library requirement. I have created a c# class that will be exposed to COM component. However, when I set a value to an array property I get a compiler error. All ...
- 210
1
vote
1
answer
736
views
Can not marshal interface from main thread into worker thread
INTRODUCTION
I am buidling in-proc COM server to be consumed by VB6 client.
COM server needs to use blocking function.
This means that the VB6 GUI would be blocked until function retrieves the ...
- 3,031
1
vote
1
answer
799
views
Use SHAssocEnumHandlers in C#
I am struggling to call the WinAPI SHAssocEnumHandlers in C#.
using System;
using System.Runtime.InteropServices;
namespace AssocHandlerTest
{
[Flags]
public enum ASSOC_FILTER
{
...
- 371
0
votes
1
answer
63
views
Can different threads reuse the same marshalled ActiveX interface?
when I marshal ActiveX interface through Global Interface Table (GIT), do I need to call GetInterfaceFromGlobal() from every thread that will use this interface? Alternatively, once one thread gets a ...
- 35
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0
answers
152
views
Why can I not mix Guid and string members in a ComVisible struct?
Consider the following interface (registered with regasm /tlb with a c# out of process server and client):
[ComVisible(true)]
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
public interface ...
- 22.2k
2
votes
0
answers
105
views
Accessing C++ arrays passed via COM in C#
I have a legacy COM class that passes C++ array pointers without using SAFEARRAY. (It was probably implemented before that existed.) I'd like to implement an interface in C# without change the COM ...
- 321
4
votes
1
answer
6k
views
Returning a string from an unmanaged c++ dll to c# [duplicate]
I'm trying to call unmanaged c++ from c# but receiving an exception about the return value.
The exception:
System.Runtime.InteropServices.MarshalDirectiveException: 'Cannot marshal 'return value': ...
- 63
1
vote
1
answer
1k
views
Marshal [in] reference without ref
Some functions, especially in COM interfaces, expose a REFIID parameter that is used to specify the type of the interface the methods should return. Here's such an example method:
[DllImport("shell32....
- 13.1k
0
votes
1
answer
169
views
Unable to ReDim array from C# class in VB6
I have to use C# class in vb6 which contains arrays.
I'm marshalling them as Safe Arrays but I can't redim them in VB6, although in watch I can see that they have correct types.
When I was using the ...
- 151
1
vote
1
answer
293
views
MSXMLl 6.0 XmlDOMNodeList fails when is invoked GetEnumerator
Our project uses MSXML 6.0 com object for working with XML through ComImport attribute. Below com Class which provides access to existing MSXML COM(I left only SelectNodes for clarify problem ).
[...
- 122
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votes
0
answers
725
views
How to pass COM parameter of type SAFEARRAY** from C#
I'm trying to call a COM interface function from C# code. This is an aggregated COM interface where I load the implementing COM interface by ProgID and I have to declare the interface myself. The c++...
- 39
0
votes
0
answers
135
views
GetEnumerator throws ArgumentException on Windows with WinRT
I оbtain xmlCollection through com objects and try to use foreach with the obtained collection. That invokes this
System.ArgumentException
at System.Runtime.InteropServices.Marshal....
- 122
4
votes
0
answers
961
views
Error 'Unable to cast COM object of type' when crossing thread apartments in C#
I've been working with a third party SDK as a referenced dll from within C# using .NET 4.5.2 on Windows 10. The IDE creates an Interop around the dll and I can see the appropriate namespaces, ...
- 307
1
vote
0
answers
2k
views
Unable to get usable data from System.__COMObject
I am working with a third party SDK (Proprietary) which I have referenced in my console app, I been tasked to help build a solution which will facilitate many everyday tasks. However, as I been ...
- 580
3
votes
1
answer
379
views
How to use IFont and IStrings in Delphi 2010?
I want to write a DCOM client/server in Delphi 2010 that uses IStrings to pass Memo1.Lines(as TStrings) as property in a test Server. The server has a TMemo component and I want to set or get its ...
- 101
1
vote
1
answer
674
views
FreeThreadedDOMDocument, Neutral Apartments and Free-Threaded Marshaler
As MSDN states:
If you are writing a single threaded application (or a multi-threaded application where only one thread accesses a DOM at one time), use the rental threaded model (Msxml2....
- 316
1
vote
1
answer
485
views
To Marshal or Not to Marshal
I could not find the definite answer to the following question: if a COM class is thread safe, that is it is marked with Both or Free, do I really need to marshal its object interface to pass it to ...
- 316
1
vote
0
answers
128
views
Passing ref object array from .net to COM server
I'm trying to convert from vb6 to vb.net and I face a picky problem.
I have to pass a reference array object to COM server from vb.net, but variant type of passed array object has VT_DISPATCH, ...
- 11
7
votes
1
answer
360
views
Pass C# object to COM by value
I'm trying to use a COM interface from C# that exposes the following interface as generated by tlbimp:
[Guid("7DDCEDF4-3B78-460E-BB34-C7496FD3CD56")]
[TypeLibType(TypeLibTypeFlags.FDual | ...
- 9,658
0
votes
1
answer
36
views
RCW does not convert integer when passing from .Net to COM
As per MSDN, regarding the conversion of types done by the RCW between .Net client to unmanaged objects, it is written:
...Other types require no conversion. For instance, a standard wrapper will ...
- 3,480
0
votes
1
answer
683
views
ReportAvOnComRelease Error with Marshal.Release()
I have seen similar errors here but can't quite determine what's causing it.
I have an IntPtr which is referencing a GetForegroundWindow() object :
IntPtr ptr = GetForegroundWindow();
This ...
- 8,081
0
votes
0
answers
195
views
Unable to access values of array passed from managed to unmanaged code
What i am trying to do :
i am trying to call a method written in a ATL COM server (a dll basically) from a c# client.i am trying to pass a c-style 1-dimensional array by reference to the method and ...
- 21
0
votes
1
answer
189
views
Passing an object in C# that inherits from a generic causes a cast exception with IDispatch
I have a COM call I would like to make
[DispId(163)]
[MethodImpl(MethodImplOptions.InternalCall, MethodCodeType =
MethodCodeType.Runtime)]
[return: MarshalAs(UnmanagedType.IDispatch)]
object ...
- 32.1k
0
votes
1
answer
354
views
Marshalling array of struct (that contains an array of struct) from C# to Delphi (managed to unmanaged)
The C# struct:
public struct Table
{
[MarshalAs(UnmanagedType.LPArray)]
public Parameters[] parameters;
public string Name;
etc...
}
public struct Parameters
{
public string ...
2
votes
1
answer
670
views
COM and Services
I'm trying to create a service to communicate with a COM object that controls on BarCode Scanner (model Motorola Symbol LS9208).
I created the TLB unit from ocx installed with scanner driver ...
- 327
2
votes
0
answers
455
views
Marshalling Variable Length Array in C#
I am processing input data from a human interface device using GetRawInputData. There is a RAWINPUT structure which contains a RAWHID structure:
typedef struct tagRAWHID {
DWORD dwSizeHid;
DWORD ...
0
votes
1
answer
600
views
C# Marshalling to call C++ DLL. COM and threading issue
When I try to call a extern method from a non-main thread, I get COM CoInitialize error from the DLL written in C++ thread.
Just for slight more details, I have define an alias to call the c++ method ...
- 1
0
votes
0
answers
145
views
C# program needs access to large dataset in C++ COM quickly
I have a C# program that wants to process some floating point data. The data comes from native C++ code that is 64 bits (a COM EXE) while the C# program is 32 bits. I can pass data back and forth ...
0
votes
1
answer
933
views
Getting ref parameter from COM with InvokeMember call
I am trying to call a method of a COM server using InvokeMember.
The method has the following signature:
void InsUpdOpInstance(
[in] long inIdOperDescr,
...
- 11
0
votes
1
answer
938
views
COPYDATASTRUCT and Marshal.PtrToStructure throws AccessViolationException
My 64-bit C# 4.5.1 WinForms application, using the following code, correctly gets a COPYDATASTRUCT message from an external 32-bit C++ DLL (over which I have no control), as shown in a Memory Window ...
- 2,839
2
votes
0
answers
2k
views
Error Creating an instance of the COM component with CLSID. WCF with COM
How can i solve the next problem that i have. Im using WCF and it reference a COM.
Creating an instance of the COM component with CLSID {...} from the IClassFactory failed due to the following error: ...
