(Note follow-up set to microsoft.public.dotnet.myservices only) We have a client-server environment where clients request services from the server via a C/C++ DLL (it is *not* COM based). The DLL has been used by many application including C++ and VB over many years. I tried to make use of this DLL in a .Net C# application by making use of DllImport as follows: [ DllImport("CodaLink.dll", EntryPoint="LinkEncrypt", CharSet=CharSet.Ansi) ] private static extern int LinkEncrypt([Out] StringBuilder Output, string Input, string UserID); I encapsulated these types of calls in a .Net DLL assembly, created a sample ..Net Console application that uses the DLL, and that ran fine. I then tried to create a .Net Windows Services and installed it using the same security context as the Console application but it is failing. I think it if failing to establish a connection to the server. I have made sure that both the Windows Service EXE and the .Net DLL Assembly are in the same directory and I've also included the containing directory into the system PATH. From the service I write the PATH to the EventLog and it does contain the containing folder as expected. The Windows Service appears to be making some calls to the DLL but I do not understand why the DLL works from a Console app but not in a Windows Service. Please help?
Services and Console applications never run in the same user context! One of the differences is that Services don't load an "interactive user profile" (HKCU registry hive) , instead, they fall back to the "default" profile. I guess your LinkEncrypt function relies on the presense of HKCU to find it's keystore. So in one word the DLL is not designed to be used from a Service. One option is to create a logon session (call Win32 LogonUser()) and load the profile (LoadUserProfile()) of an interactive user. Willy. "Tushar" wrote in message news:uo6O2CBbFHA.724@TK2MSFTNGP12.phx.gbl... > (Note follow-up set to microsoft.public.dotnet.myservices only) > > We have a client-server environment where clients request services from > the > server via a C/C++ DLL (it is *not* COM based). The DLL has been used by > many application including C++ and VB over many years. > > I tried to make use of this DLL in a .Net C# application by making use of > DllImport as follows: > > [ DllImport("CodaLink.dll", EntryPoint="LinkEncrypt", > CharSet=CharSet.Ansi) ] > private static extern int LinkEncrypt([Out] StringBuilder Output, string > Input, string UserID); > > I encapsulated these types of calls in a .Net DLL assembly, created a > sample > .Net Console application that uses the DLL, and that ran fine. > > I then tried to create a .Net Windows Services and installed it using the > same security context as the Console application but it is failing. I > think > it if failing to establish a connection to the server. I have made sure > that > both the Windows Service EXE and the .Net DLL Assembly are in the same > directory and I've also included the containing directory into the system > PATH. From the service I write the PATH to the EventLog and it does > contain > the containing folder as expected. > > The Windows Service appears to be making some calls to the DLL but I do > not > understand why the DLL works from a Console app but not in a Windows > Service. > > Please help? > >
Thank you for the reply. The service installer is set to "User" and it prompts me for UID/PWD during InstallUtil. In the services applet the LogOnAs column contains my account for the servcie (because that is what I used.) Does this not mean that the service runs in my user context? As a test I changed the registry HKCU with invalid server settings and the servcie came up with a different error. When I put the settings to correct values it is coming up with a different error which proves that it is reading HKCU. I also performed another test: I set the PATH for my accout (not system) to zzz. In command prompt this appends my PATH to my system PATH. In the service I dump the path the the EventLog that does include my local path. I therefore conlcude that the service is running in my user context. Please help. "Willy Denoyette [MVP]" wrote in message news:ud7%23GNBbFHA.3280@TK2MSFTNGP09.phx.gbl... Services and Console applications never run in the same user context! One of the differences is that Services don't load an "interactive user profile" (HKCU registry hive) , instead, they fall back to the "default" profile. I guess your LinkEncrypt function relies on the presense of HKCU to find it's keystore. So in one word the DLL is not designed to be used from a Service. One option is to create a logon session (call Win32 LogonUser()) and load the profile (LoadUserProfile()) of an interactive user. Willy. "Tushar" wrote in message news:uo6O2CBbFHA.724@TK2MSFTNGP12.phx.gbl... > (Note follow-up set to microsoft.public.dotnet.myservices only) > > We have a client-server environment where clients request services from > the > server via a C/C++ DLL (it is *not* COM based). The DLL has been used by > many application including C++ and VB over many years. > > I tried to make use of this DLL in a .Net C# application by making use of > DllImport as follows: > > [ DllImport("CodaLink.dll", EntryPoint="LinkEncrypt", > CharSet=CharSet.Ansi) ] > private static extern int LinkEncrypt([Out] StringBuilder Output, string > Input, string UserID); > > I encapsulated these types of calls in a .Net DLL assembly, created a > sample > .Net Console application that uses the DLL, and that ran fine. > > I then tried to create a .Net Windows Services and installed it using the > same security context as the Console application but it is failing. I > think > it if failing to establish a connection to the server. I have made sure > that > both the Windows Service EXE and the .Net DLL Assembly are in the same > directory and I've also included the containing directory into the system > PATH. From the service I write the PATH to the EventLog and it does > contain > the containing folder as expected. > > The Windows Service appears to be making some calls to the DLL but I do > not > understand why the DLL works from a Console app but not in a Windows > Service. > > Please help? > >
It's most definitely a permissions issue. Is the DLL trying to access a "protected" resource... or something via a UNC path (off the box)? You may want to change the account under which the service is running. -Gene "Tushar" wrote in message news:uo6O2CBbFHA.724@TK2MSFTNGP12.phx.gbl... > (Note follow-up set to microsoft.public.dotnet.myservices only) > > We have a client-server environment where clients request services from > the > server via a C/C++ DLL (it is *not* COM based). The DLL has been used by > many application including C++ and VB over many years. > > I tried to make use of this DLL in a .Net C# application by making use of > DllImport as follows: > > [ DllImport("CodaLink.dll", EntryPoint="LinkEncrypt", > CharSet=CharSet.Ansi) ] > private static extern int LinkEncrypt([Out] StringBuilder Output, string > Input, string UserID); > > I encapsulated these types of calls in a .Net DLL assembly, created a > sample > .Net Console application that uses the DLL, and that ran fine. > > I then tried to create a .Net Windows Services and installed it using the > same security context as the Console application but it is failing. I > think > it if failing to establish a connection to the server. I have made sure > that > both the Windows Service EXE and the .Net DLL Assembly are in the same > directory and I've also included the containing directory into the system > PATH. From the service I write the PATH to the EventLog and it does > contain > the containing folder as expected. > > The Windows Service appears to be making some calls to the DLL but I do > not > understand why the DLL works from a Console app but not in a Windows > Service. > > Please help? > >
Are you admin of your computer? It could be that the service has less right than you and Interop requires a high level of trust "Tushar" wrote in message news:uo6O2CBbFHA.724@TK2MSFTNGP12.phx.gbl... > (Note follow-up set to microsoft.public.dotnet.myservices only) > > We have a client-server environment where clients request services from > the > server via a C/C++ DLL (it is *not* COM based). The DLL has been used by > many application including C++ and VB over many years. > > I tried to make use of this DLL in a .Net C# application by making use of > DllImport as follows: > > [ DllImport("CodaLink.dll", EntryPoint="LinkEncrypt", > CharSet=CharSet.Ansi) ] > private static extern int LinkEncrypt([Out] StringBuilder Output, string > Input, string UserID); > > I encapsulated these types of calls in a .Net DLL assembly, created a > sample > .Net Console application that uses the DLL, and that ran fine. > > I then tried to create a .Net Windows Services and installed it using the > same security context as the Console application but it is failing. I > think > it if failing to establish a connection to the server. I have made sure > that > both the Windows Service EXE and the .Net DLL Assembly are in the same > directory and I've also included the containing directory into the system > PATH. From the service I write the PATH to the EventLog and it does > contain > the containing folder as expected. > > The Windows Service appears to be making some calls to the DLL but I do > not > understand why the DLL works from a Console app but not in a Windows > Service. > > Please help? > >
Yes I think that is the case however I've solved the problem another way (but is not elegant). I am trying to make contact the people to wrote the original API that the service is calling. I am being told that that API is trying to access some COM component and requires access to some registry setting that is not available to Windows Services. They tell me that I should call the API from an application instead as opposed to Windows Service. I therefore tried to ShellExecute another test EXE from the Windows Service and that EXE would be running (one would assume) in the same context as the service itself but (surprise, surprise) the application works. Even if this has solved my problem, I do not understand why? Why does a service run in a different context to the application that the same service is calling? *** Pleeeeeeeeease help!!!!!!!!!! *** "Lloyd Dupont" <net.galador@ld> wrote in message news:OyElt8HbFHA.2128@TK2MSFTNGP14.phx.gbl... Are you admin of your computer? It could be that the service has less right than you and Interop requires a high level of trust "Tushar" wrote in message news:uo6O2CBbFHA.724@TK2MSFTNGP12.phx.gbl... > (Note follow-up set to microsoft.public.dotnet.myservices only) > > We have a client-server environment where clients request services from > the > server via a C/C++ DLL (it is *not* COM based). The DLL has been used by > many application including C++ and VB over many years. > > I tried to make use of this DLL in a .Net C# application by making use of > DllImport as follows: > > [ DllImport("CodaLink.dll", EntryPoint="LinkEncrypt", > CharSet=CharSet.Ansi) ] > private static extern int LinkEncrypt([Out] StringBuilder Output, string > Input, string UserID); > > I encapsulated these types of calls in a .Net DLL assembly, created a > sample > .Net Console application that uses the DLL, and that ran fine. > > I then tried to create a .Net Windows Services and installed it using the > same security context as the Console application but it is failing. I > think > it if failing to establish a connection to the server. I have made sure > that > both the Windows Service EXE and the .Net DLL Assembly are in the same > directory and I've also included the containing directory into the system > PATH. From the service I write the PATH to the EventLog and it does > contain > the containing folder as expected. > > The Windows Service appears to be making some calls to the DLL but I do > not > understand why the DLL works from a Console app but not in a Windows > Service. > > Please help? > >
