Develop Reference

How can we use pgSQL in Automation Anywhere?

I have created DLL using pgSQL(to read data and return to Automation Anywhere) and I am trying to use it in an Automation anywhere bot. But it shows an error:
Could not load file or assembly 'npgsql, Version=4.0.2.0, Culture=neutral, PublicKeyToken=5d8b90d52f46fda7' or one of its dependencies. System cannot find the file specified.
if you have any idea to solve that please help me.

You can try placing all(copy paste) the necessary assemblies ( DLLs) that are required for pgSQL in your DLL function to be invoked into AAE Program files directory. Since Player couldn't load the dependencies of your dll It is throwing this exception.
Another place where you can copy is while running bot see where your dll is located and put all necessary dependent assemblies there When you run your metabot AAE creates temporary folder where it copy your dll. copy dependencies there

You need to add the dependencies you used whilst creating the DLL into the metabot as well, by uploading them alongside your DLL in the assets view. In this case 'npgsql.dll'.
If you've built the DLL on another machine, you can - in addition to the steps above - also try adding the dependent DLLs to the PATH.

Loading c++ dll in Asp.net Web App using winmd file

I have a c++ dll, and an idl file that was used to generate a .winmd file.
I created a C# application that consumes the .winmd file and I can successfully create an object for a class that was defined in the dll. i.e the program compiles and runs without any issues.
However, when I try and use the same exact winmd file (which works when consumed by a C# application) for a C# Asp.net web app (i.e I add a reference to the winmd file and I see that the winmd file and dll are copied into my web apps bin folder), I get a runtime exception saying:
"Could not find Windows Runtime type [Name of class]"
When I use Fusion Logs to see what went wrong when the application was attempting to load the dll, I see this:
END : Typename or Namespace was not found in metadata file. (Exception from HRESULT: 0x8000000F)
So my question is, what is the main difference between loading a native dll in a C# application vs an Asp.Net application?

How to deploy a dependent DLL when a client solution references my project?

I have a C# project which builds a library DLL, myLib.dll. This DLL has a dependency on a 3rd party DLL, dep.dll (which I provide but do not build).
I want others to be able to use my library by adding my project to their solutions and referencing it. Adding my project as a reference automatically copies myLib.dll to the Target directory of their app, but of course dep.dll is not copied with it.
Bear in mind that I have no control over where my project is in their code tree, and the DLL can't know where it was copied from.
The only solution I can see is to force the user to add a build event which copies dep.dll to their target directory. We can't assume users can create environment variables.
This is very undesirable for several reasons (it's not really one dependency - I simplified things, I don't want them to have to be concerned about the dependencies in my project, and it's very fragile - adding an extra dependent DLL to my project would require everyone to update their build scripts).
I can't load the dep.dll directly as I don't know where it is - my build scripts can copy it to the same target directory as myLib.dll but the actual version of myLib.dll they run will have been copied somewhere else.
I also can't make dep.dll a reference directly (probably because it's not a .NET assembly). I just get "Error loading code-completion information for dep from dep.DLL. Format of the executable (.exe) or library (.dll) is invalid".
So is there any way to have the dependent DLL just seamlessly copied with myLib.dll when a client builds their application? [I'm using Sharp Develop if it matters.]

Can you add dep.dll to your projects root folder as a file like a .cs file. Set the Build Action to None and Copy to Output Directory to Copy if newer.

dll not found (non COM object)

I made an application in vs2010 (.net 4.0). I published it, both using publisher and InstallShield LE.
But when I run application, I get error that a dll is not found. I know which dll is missing. This is a non-COM object and I can't add it to my project in vs2010. I am using a wrapper library which invokes this dll.
If I paste that dll in syswow64, my application works fine. But I want a cleaner way of doing it. I already had a look at Hans's answer here. But I have no clue what is side-by-side cache.
Adding path to environment variables works fine too.
I am not sure if updating registry and adding a path value will work or not. I would like to know if I can update registry for my application and direct the path where it searches for particular dlls.
Thanks.

Modifying the user's PATH variable is a very heavyweight solution, and you should avoid that. Likewise, do not put the DLL in the system directory. That belongs to the system and is private to you.
The recommended way to solve the problem is simply to put the DLL in the same directory as the executable. The directory in which the executable lives is searched first when the loaded tries to locate DLLs. It is the safest place to put your native DLLs.
If for some reason you cannot put the DLL in the executable directory, there are other options:
Call SetDllDirectory with the directory of your DLL before making your first p/invoke call. When that call returns, call SetDllDirectory passing NULL to restore the default DLL search order.
Make an explicit call to LoadLibrary with the full path of your DLL before making your first p/invoke call. Once the DLL has been loaded, future p/invoke calls will use the module that has been loaded.

If you know the DLL name in advance, there is a simple way.
You can simply use LoadLibrary to load the DLL from its known location (based on for example a configuration file entry).
As long as you successfully call LoadLibrary before any of the DLL methods are used, this will succeed as the DLL is already loaded.
This works because you can LoadLibrary with a full path, and once that is done, subsequent calls to LoadLibrary with just the filename will succeed immediately, since the library is already loaded.

iis7 hosted wcf service : avoid placing dll in system32 folder

I have a wcf service referencing a dll. Only way it works is by placing the dll in %windir%/system32 folder.
Things I have tried
tried switching between iis express, development server and iis (but this is irrelevant)
placing the dll in the bin folder and/or other application folders
trying to use the "regsvr32" util but the dll is not a com dll so it does not work.(no ddl entry point)
It is not a .NET dll so I don't think GAC can be manipulated to work with this
played with the system path variable without any success
What I actually want
A simpler method to access the dlls so I do not have to place the dll in system32 but contain it in an application folder and access it from there.
What am I missing?
EDIT:
I did find this post interesting and similar but again, it also uses the system32 method which is not the way to go.

If this is a win32 native library, you can "preload" it from a known location using pinvoked LoadLibrary passing a full path of your library as a parameter, somewhere early in your processing pipeline.
When any method from the library decorated with DllImport is called, the runtime will try to load the library (and would fall because the dll cannot be found) but since you preloaded it eariler, loading will succeed (loader checks the library file name, doesn't pay any attention to the directory the library is loaded from).