I am trying to use a function in an unmanaged dll and I am getting a System.NullReferenceException when called. I do not have source code for the vendor dll. >From the dll header file the declaration is: WEBEXPORT char* function1; vb.net ------ <DllImport("vendor.dll")> _ Public Shared...more >>

I need to implement a COM interface in VB.NET and C#.NET. The interface has the following method: void SetObjects([in] SAFEARRAY(LPUNKNOWN) objects); In other words, I need to pass an array of IUnknown pointers to VB or C#. I can change the interface however I want. My goal is to make t...more >>

Hey Everyone In my current project, which is invloving making enhancements to an old VB6 application, I need to do following things: 1. Call a .Net WinForm (present in a .net dll) from a VB6 MDI application 2. The called WinForm should behave like a child form of the main MDI form in the VB6...more >>

Been trying to get WinXP themes to work in an Office COM Add-in. I came across this article: http://support.microsoft.com/default.aspx?scid=kb;en-us;830033 which had a C# example. All good, until I hit the juicy statement at the end, which makes it all work: using( new EnableThemingIn...more >>

My goal is to create a remote installation program to rollout program installs and updates. We're a small company with about 60 workstations, so it's not worth the investment in SMS. I have the first part working which used the directory services namespace to enumerate the workstations in a ...more >>

I am using visual c#.net to do Mail Merge with Microsoft Word 2003. When the word document has 18 or more merge fields, the merged document works fine, but creates a blank page at the end. Please let me know, if you have a solution for this issue. ...more >>

I am writing a C++ program that is using a C# control. It calls a function that requires a handle to data in memory. If I set up the C# function to take this parameter as a uint, it works fine. I would rather set up the parameter as an IntPtr. But when I do that, I get an exception when the C++ ...more >>

Folks, Quick question. I've created a .NET library component that will be used by some of my MFC C++ customers by making the .NET component COMVisible (ie I will create the .NET Component in C++ as a COM object). I'm creating a simple MFC Dialong application to test the component. Everythi...more >>

I have a .Net class in a dll that compiles code on the fly. Everything is working great from all .Net applications. I'm now trying to make this class Interopable. I don't receive any erros after calling CompileAssemblyFromSource but when I try to create a instance of my class (CompiledAss...more >>

Hi, We have a large application built with a PlugIn/SnapIn technology in VB6 today. We are now in the process of upgrading it to .NET 2.0. But of course we cannot convert all SnapIns at once, some of them might exist for a long time. So we need to use Interop... However, when one of the...more >>

I have searched marshaling articles from MSDN and Google but I am stuck with solving my problem to marshal arrays to COM caller from my managed COM class I built a .net COM class in VB and tested it from an application built with C tool.. It worked well except for those functions in the ...more >>

I'm sure it's something simple I'm overlooking but... I have a .NET app written in C#. I imported a couple of different COM servers via the Add Reference->COM window. I then start up the servers by "new"ing them up (see example code below). The server starts up correctly. The problem is that w...more >>

Hi, Appologise for the cross post, but this fits both in Excel and .NET world. I've got a requirement to build a windows app for a specific type of financial modelling. My ideal position would be to write a .NET windows form app that embeds an excel worksheet in the way a grid control woul...more >>

Hi there, I'm working on a simple VB.NET app in Visual Studio 2003 that uses classes in the msxml4.dll. I added a reference in my project to the msxml4.dll and VS created the Interop.MSXML2.dll. However, when I attempt to execute the program, I get an error stating that the COM object wi...more >>

Is it possible to show a C# winform that stays within an unmanaged C++ MDI client area? Basically, I want the winform to behave like a standard view window. If it is possible, how can I accomplish it? Thanks ...more >>

Hello All, I've recently come accross a problem when trying to work with a unmanaged dll compiled in C++ (Visual Studio 6.0). When calling the dll from my C# application primitive data works okay for converting PLONG, INT, BOOL to the right function signature. For example: C++ Function: LO...more >>

Hi, I'm getting a 'Type mismatch' exception when calling the Word.Application.Documents.Open method when using the Office XP 2003 PIAs. the actual error is: System.Runtime.InteropServices.COMException (0x80020005): Type mismatch. This method works when using the Office XP PIAs (not that ...more >>

Hi, I'm getting this error "Access is denied" in my Web Application when I try to communicate with a Com object that I have. It's running under Windows 2000 Server. Can anyone help??? -- Programming ASP.NET with VB.NET Thank's (if you try to help me) Hope this help you (if I try to h...more >>

I'm having problems with Forms Authentication in a hosted environment. On our in house server and on my development machine everything works correctly However in a hosted environment, when clicking on a link to any exe file in my download\installs folder the login page is not displayed and...more >>

Hi, I have some C++ native clients that need to interact with managed assemblies for which there are existing idl files (these assemblies are migrations from C++ to C#). The C++ clients use idl files to build the .tlh and tli files so they can interact via COM with the assemblies. Using #...more >>

Hello, I have a Win32 DLL that I call, it works perfectly when the methods are called from the main process of the application (witch is a ASP.NET site) but when called from a new thread it gets locked inside the call. Just to exclude any type problems & lockings I have exported a test meth...more >>

Hi, I would like to use one of the error codes defined in WinError.h. There is no iclude anymore. I have put in "using System.Runtime.InteropServices" and the compiler still doesn't recognize the error code. There must be some way, other than defining it by myself... Anybody ? ...more >>

I have a registered COM application (.exe) that creates a telnet session upon startup. If the application is running I can use GetActiveObject("Reflection1.Session") to get a reference to the Session interface of the running application. Using Process.Start("path to exe") I can even get th...more >>

In OLE/COM Object Viewer, I found Excel Interface _Worksheet like this. [uuid(000208D8-0000-0000-C000-000000000046)] [helpcontext(0x00020010), dual, nonextensible] dispinterface _Worksheet { // : // : [id(0x000000c5), propget, helpcontext(0x000100c5)] Range* Range([in] VAR...more >>

I've got a structure I'm trying to marshal to a custom.dll I'm missing something, because some of the values marshal, others do not. I dummied up a .dll so I can see both sides of the problem, but that's not been much help.. When I call the function, the strings marshal fine, as do the b...more >>