Force program to use the dll from the %temp% folder - c#

I want to force the compiled program to use the dll from the %temp% folder.
However, if I do like that
compars.EmbeddedResources.Add(Path.GetTempPath() + "\\Newtonsoft.Json.dll");
compars.ReferencedAssemblies.Add(Path.GetTempPath() + "\\Newtonsoft.Json.dll");
The program crashes.
I have also added using Newtonsoft.Json.dll but I still need to have the Newtonsoft.Json.dll in the same folder as my program, if so, the program isn't crashing, otherwise it crashes even if Newtonsoft.Json.dll is in the %temp% folder. So in general, I want to run the program successfully without having the dll in the same folder, and force it to use the dll from the %temp% or something like that.

You can embed other dlls into your program easier. Please refer to the following link:
stackoverflow.com/questions
You can also use ILMerge to do it automatically.
You can also surround your code with try-catch to get more detailed information. I guess your dll's version is not equal or some similar issues.

Adding the referenced assemblies to the compiler parameters (I assume that is what compars is referring to) will make sure the compiler uses that dll as reference at compile-time. During execution of the compiled program, the operating system will try to locate the referenced assemblies in the "usual way".
There are so many detailed specifications on this that you could read them 24/7 until your death (e.g. https://learn.microsoft.com/en-us/windows/win32/dlls/dynamic-link-library-search-order).
But to accomplish what you want, namely to have the compiled program use the specific dll from your temp folder at run-time, you can merge it with ILMerge as suggested in Mostafa Khodakarami's answer. The library will become an integral part of yours. Your dll will not be at risk of failing to find the needed reference, but it will also not use a newer version of the referenced library if one is available. Depending on how you do the merging, you also might not be able to share objects created with the library with other third party libraries that also use it, unless you also merge them.
Another tool to do the merging is ILRepack (see https://github.com/gluck/il-repack) which touts itself as being better than ILMerge. We switched from ILMerge to ILRepack because we reached some kind of internal limit on the number of objects in ILMerge.
Finally, you could also have your program load the dll itself "manually" by using
public static System.Reflection.Assembly LoadFrom (string assemblyFile);
(see https://learn.microsoft.com/en-us/dotnet/api/system.reflection.assembly.loadfrom?view=net-6.0)
Call the method like this at the beginning of your program, before any methods are called or objects created that use that library:
Assembly.LoadFrom(Path.GetTempPath() + "\\Newtonsoft.Json.dll");

Related

How to call tool DLLs in C# when the DLL-path is different on the target PC?

I might be a bit stupid, but I want to create a tool in Visual Studio in C# and want to call third party tools via their API-DLLs. The only topics I found here are dealing with one of the two methods that I already know:
Compilation time: add a reference to "C:\FooTool\foo.dll" in my project + "using fooToolNamespace.fooToolClass" in my code (compilation time) --> I can "naturally" use the classes of the DLL and will even get full IntelliSense support if a suiting XML-file is available with the DLL. Also compilation time checks will be done for my usage of the dll.
Dynamic (run time): calling e.g. Assembly.LoadFile(#"C:\FooTool\foo.dll") and then using reflection on it to find functions, fields and so on --> no IntelliSense, no compilation time checks
So I actually have the DLL at hand and thus option 1) would be nice during development. But if my tool is used on a different PC, the third-party DLL might be in a different path there, e.g. "C:\foo\foo.dll" and "C:\bar\foo.dll".
In my understanding using a copy of "foo.dll" will not work, because "foo.dll" might have dependencies, e.g. requiring other files of the FooTool-directory. Thus in my understanding I have to call the DLL which is "installed" to the target PC and not a local copy of it.
So can I somehow change the path where my tool accesses the "foo.dll" at runtime and still use method 1) during development?
Or is there another way of doing things?
Or am I just dumb and there is a simple solution for all this?
Thanks a lot for the help and have a great day
Janis
To be able to use option 1 (a referenced DLL), you need to put the DLL somewhere "where your EXE (or, more precisely, the Assembly Resolver) can find it" on the customer's PC.
So where does the assembly resolver look for your DLL?
In the directory where the EXE resides (for desktop/console applications) or the bin subdirectory (for web applications). Since you mention that your DLL requires other dependencies as well, you'd need to copy them to that location as well.
The Global Assembly Cache (GAC). If your dependency supports this, installing it to the GAC ensures that it can be found by your application.
These two are the "supported" scenarios. There is also the possibility to tweak the assembly resolver to look into other directories as well, but that should be reserved for special cases where the other two options failed. (We had such a case and solved it with a custom AssemblyResolve handler on the application domain.)

How to create a dll that includes all the others?

At the moment of creating a project of type "Library of Classes, usually one can generate a dll when compiling, but how could I generate a dll without losing others that I already have included?
I explain with an example: It turns out that Nuget downloaded an S22.Imap dll with the one I worked with, later I generated the dll in the traditional way that I explained in the beginning, but when I wanted to work with dll in another computer, I got errors that were not I found functions that contained the S22.IMAP dll. So to solve this problem, I had to copy the dll of my project, S22.IMAP in an additional way in a specific path of the other computer.
My question is:
How could you generate a dll that includes the ones included in the project you were working with?
All the referred 3rd party dlls (S22.Imap.dll in your example) will be copied to the output folder together with your own dll file (let's say a.dll) when you build your project. That means you should always copy them together (S22 + a.dll) to the place you want to refer them, on another computer/folder/place.
If you really want to make them only one file (although it is not recommended), you can set the S22 one as some "nested resource". Then you will get only one a.dll file and the S22 one is inside the a.dll. See below page for some reference:
Embedding one dll inside another as an embedded resource and then calling it from my code
AND, ILMerge is some tool that can help you do so.
In general, you don't. A DLL is a dynamic linked library, and you would normally only combine static libraries during a build. Here is an answer on the difference between static and dynamic linking.
Typically you would include all the DLLs you need in the installer package. If you use Visual Studio to create the installer, it can detect the dependencies for you. When you run the installer, all of the necessary DLLs are deployed. Nearly all commercial .NET software follows this pattern.
It is possible to merge an assembly into another assembly using a tool called ILMerge. This would be a very unusual thing to do, and could cause issues with intellectual property and code signing, so it is not recommended.

Is there an easy way to modify a decompiled file without having to deal with its dependencies?

I managed to decompile a c# file (using dotpeek) and I want to edit a couple of simple things (using visual studio).
The problem is this file has many dll dependencies even though the edits are necessary only on the main exe.
Obviously if you try to build an exe on vs without having the references and dependencies in place the compiler will complain. Are there any solutions to this?
You cannot build without the dependencies; however, there is no need to decompile the dependencies. Just add the DLLs themselves as reference to the project.
This is always fine if the decompiled assembly depends on other DLLs; however, if the other DLLs depend on the decompiled assembly, this will only work if the assemblies are not signed, i.e. if they are not using strong names. The purpose of signing is precisely to disallow such hacks.
No, you can't build without the dependencies because the compiler has to check that types match and have the indicated members etc.

c# Use dll with different versions in one directory

How can I use different dll's (other Version) with the same name in one directory?
For Example, LibA (ExternalLib.dll) has Version 1 and LibB (ExternalLib.dll) has Version 2.
I'm deploying all my programs to the same directory (this is our companys standard and I can't change this fact). The problem is if ProgramB which is using the LibB is deployed in the directory where ProgramA is using the LibA then ProgrammA would not longer work.
For my own Libs I use a Major-Version-Number (.01, .02) if there are big changes. But the Lib I'm using is an external Lib and each version of it requires different licensing-keys (which are handled by the programs itself).
I tried to rename the external libs from "ExternalLib.dll" to "ExternalLib.v1.dll" and "ExternalLib.v2.dll", but when I run my fresh compiled programm it throws an exception that says "ExternalLib.dll could not be found". The reference in my project is set to "ExternalLib.v1.dll" and compilation works fine.
Any ideas / suggestions to handle different assembly versions in the same directory?
Unfortunately, the filename of the DLL file has very little do do with how .Net is loading these types. The actual name is written into the meta data of the assembly as part of the compilation process. So at runtime, it will be probing for ExternalLib.dll regardless of what you renamed the file to. The usual way to fix this is to install to the GAC and use Strong Naming to reference the specific version.
Given you may not be able to do this, there are 4 things you could try:
Ask the vendor to produce version specific DLL's for you. They could compile such that the version name is part of the filename and included in the assembly manifest. This would be the simplest solution for you.
Handle the AssemblyResolve event and manually try and use Assembly.Load to point at the file you want such that you can specify specifically which dll to use. See http://support.microsoft.com/kb/837908 for more information, but effectively you'll be using Assembly.LoadFrom(specific_path) to choose the file where the code will load from.
If possible, you might also be able to use ildasm.exe to decompile the dll's to Intermediate Language (IL), then use ilasm.exe to recompile it to a new dll name. You would then reference this new DLL name in your project.
If the assembly is not signed, then you may be able to edit the manifest yourself; you can either use a compatible binary editor or possibly MT.exe.

The .NET equivalent of static libraries?

I'm building a tool in managed code (mostly C++/CLI) in two versions, a 'normal user' version and a 'pro' version.
The fact that the core code is identical between the two versions has caused me a little trouble as I want to package the resulting tool as a single assembly (DLL) and I don't want to have to include the .cpp files for the common code in the projects of the two versions of the tools. I'd rather have a project for the common code and a project for each version of the tool and have each version of the tools project depend on the common code and link it in as desired.
In unmanaged C++ I'd do this by placing the common code in a static library and linking both versions of the tool to it. I don't seem to be able to get this to work in C++/CLI. It seems that I'm forced to build the common code into a DLL assembly and that results in more DLL's than I'd like.
So, in summary, I can't work out how to build the common code in one project and link it with each of the final product projects to produce two single DLL assemblies that both include the common code.
I'm probably doing something wrong but I tried to work out how to do this using netmodules and whatever and I just couldn't get it to work. In the end the only way I got it working was to tell the linker to link the build products of the common code assembly rather than the results which works but is a bit of a hack IMHO.
Anyway, does anyone have any suggestions for how I SHOULD be solving this problem?
Edited: I guess I should have mentioned the fact that the assemblies generated are not 100% managed code, they contain a mix of managed and unmanaged code as is, probably, quite common with assemblies produced with C++/CLI...
If you are annoyed at all the DLLs, download ILMerge. I use this to bundle together multiple DLL's into an easy-to-use .EXE for my clients.
If I'm understanding this correctly, you have a solution which contains two projects. One project for the "normal" user and one project for the "pro" user. Visual Studio allows you to add a "link" to another file source from another project. If your "pro" version has the real core code file, and in your "normal" version you add existing -> find the file in the "pro" project, and click the down arrow by the Add button and select "Add as Link". Now you have single file that is literally the same between two projects.
As said, ILmerge is one way. Personally, if you're bundling some exe with a lot of DLLs, I favor Netz.
You could use modules. You can link them into an assembly using the assembly linker, al.exe.
That's the downside of the .Net compilation process, you can't have things like static libraries and the header files that hold them together, everything is held in one big dll file and the only way to share information is to either build a common dll and reference it from other assemblies or to duplicate the code in each dll (possibly by copying/linking .cs files between projects).
Note that the 2nd way will declare different types, even though they have the same name. This will bite you on the ass with stuff like remoting (or anything that requires casting to specific shared interfaces between processes).
Remotesoft Salamander will hook you up. It's basically a native compiler and linker.
When using mono (or cygwin is an option) mkbundle may also be a valid choice.

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