I have multiple DLLs (either managed myself or not managed myself) that I would like to include in a CoreLib.dll so that I do not have to include (possibly) hundreds of DLLs in every application that uses these DLLs. I include the DLLs with a reference directly to the DLL.
So, I would also like to instantiate classes declared within those DLLs in the application I am creating. I cannot do what is pictured in MyApp.exe project, even though I would like to. There is no reference to A, B or C in CoreLib.
How can I accomplish what I want?
EDIT
I used Facade Pattern as suggested, however I am getting a compilation error. Its saying I have to include A.dll in MyApp project. Why? This is what I wanted to avoid. Any way around this?
I do not think this is possible. Adding reference to A, B and C DLLs in CorLib will only mean that CorLib references these DLLs (AssemblyRef metadata table will have one record for each assembly). This does not mean CorLib redefines the assemblies and any types of the referenced assemblies. in MyApp.exe, you would need to reference A, B and C assemblies.
An alternative solution would be to define a Facade class in CorLib and redirect calls to A, B and C DLLs. In MyApp.exe, you will use the Facade class.
You can use ILMerge to merge the assemblies into one.
Then you can use all the classes in that assembly the way you want to.
Here's an example how to merge several assemblies (dlls) into one assembly (dll):
http://www.fishofprey.com/2011/01/ilmerge-to-combine-multiple-dlls.html
Essentaily you just do
ILMerge.exe /out:CoreLib.dll A.dll B.dll C.dll
I think you are confusing DLL (which is in native managed world contain actual implementation) with LIB/OBJ files that contain something that will be merged into EXE/DLL at build time to include implementation into corresponding EXE/DLL.
You have essentially 2 options:
carry all DLLs with your application (normal approach, should be taken unless you have strange requirements). You can either reference assemblies directly from your main application and create classes or make some sort of factory in your CoreLib assembly that will create classes on demand. In later case you may not need to add references to all A..C assemblies (if you not using classes directly, but via some shared interfaces/base classes), but still need to carry them around.
some sort of merging assemblies into one (i.e. ILMerge as suggested by #Alex). This approach would require better understanding of CLR than first one and may not be possible if third party assemblies are involved (due to licensing).
Related
I have two projects:
ProjectMain (class library)
LibraryProject (class library)
ProjectMain is a class library that should only be compiled as a singular library, no referenced libraries. I require a static class reference from LibraryProject BUT I don't want the LibraryProject assembly to be compiled together with the ProjectMain assembly.
I've tried 'link references' in visual studio but this is no solution as the library assembly is always compiled with the main assembly.
There are clear standard solutions to this issue but I am severely limited by the existing implementation requirements. Only one DLL can be compiled without any of the dependent assemblies being in the execution folder, GAC, private path, reflection etc.
The exact limitations are as follows:
Assembly executed in a sandbox from a third party provider, it only supports adding a single assembly with no direct references/reflection etc (it's horrible but my hands are tied)
We would like to handle the code organisation as best possible which means following standard best practices, unfortunately, due to the above limitation that's proving difficult.
What I would like to know is if there is a way to reference a class within another project without also compiling/using that referenced classes assembly. Possibly a method where the compiler 'embeds' the referenced class at compile time.
If your sandbox does not allow loading other dlls in AppDomain, load it yourself by embedding it. You can use Costura.Fody for this purpose, it is easy to use/install, just reference it from nuget.
Of course, embedding it in every scenario is madness and often comes with completely obscure bugs, which often solvable only by enabling traces in regedit.
So, in your case I would create two projects:
MyDll.csproj //it is my original project, with perfect code design and etc. Lovely.
MyDll.Sandbox.csproj //this one is the same as MyDll.csproj, except it is compiled with additional Costura.Fody reference, into single dll (every reference is put inside)
This way you just need to maintenance that MyDll and MyDll.Sandbox files are the same.
TL:DR How do I reference an assembly only in a class library rather than both the library and the calling project?
I am building a utility library in C# in order to promote code reuse. In this instance, I am wanting to do something things with a TFS server and need to reference several assemblies from the TFS side of things:
Microsoft.TeamFoundation.Client
Microsoft.VersionControl.Client
Microsoft.WorkItemTracking.Client
I include these references in the class library called, say, Utility. I then proceed to wrap objects in those assemblies in helper objects. There are no errors, intellisense works correctly, and so forth.
When I want to use that class library in another project inside the same solution, say, TestCLI, I add a reference to the Utility project by selecting the project from the solution references tab. I can then use the Utility classes without issue, until I go to build.
When I build the solution, it throws an error such as:
The type 'Microsoft.TeamFoundation.VersionControl.Client.BranchObject' is defined in an assembly that is not referenced. You must add a reference to assembly 'Microsoft.TeamFoundation.VersionControl.Client, Version=12.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
In the past, I have worked around this issue by adding the same references to the calling project (TestCLI) in addition to the class library (Utility). I feel that this is defeating one of the purposes of having a class library and that I've missed a step in order to not have to worry about library references in my calling project.
Is there some way to resolve these dependencies without including the references in both the class library and the calling project? Am I structuring my solutions incorrectly? Am I thinking about class libraries in the incorrect manner?
The references are required because you are exposing objects from the other libraries, and then to use these classes the final program needs the references.
To avoid this you must hide the external objects, through a wrapper, a copy of the class or anything else, it depends primarily on what and why you are exposing those objects.
I have a project which needs to indirectly use three different versions of a third-party library. These versions are incompatible with each other, so I can't use a binding redirect - it has to be the exact .dll file. (The libraries are Spire.Doc, Spire.XLS & Spire.PDF; the Spire.PDF DLL is referenced by all three)
I have separated the three components into individual wrapper projects, and created classes which wrap direct references to anything in the libraries. However, this doesn't solve my issue: the 'consuming' project still has to copy all of the libraries to the bin folder in order to run. The build process doesn't know which version to copy, and so just copies the latest one. This gives me runtime exceptions due to the wrong DLL being present.
What I've considered/tried:
Adding a binding redirect to a specific version (runtime exception because the exact version of the library is not found)
Using a post-build step to merge the wrapper projects (again a runtime exception complaining about the absence of the library DLL)
Creating separate console applications for each part of the application, then invoking them in a separate - this is a complicated last resort that I'd really rather not do!
I have read that extern alias might be able to help - but as far as I can tell, you can only distinguish between assemblies with different names. The Spire.PDF library has the same name in each project (and the same signed public token).
How can I use these three separate versions of the library independently in the same solution?
Edit:
This issue is slightly different to the suggested duplicate because I don't have the ability to change any code in the dependent libraries. Spire.Doc relies on a different version of Spire.PDF to Spire.XLS
In your consuming project (Project A), create a common interface (ISpiroPdfAlex) that encompasses all the functionality that the 3 versions of your external assembly provides (and you use). You cannot reference anything in Project A from these wrappers in any way, otherwise you'd create a dependency, which is what you're trying to avoid.
Have all 3 wrapper projects import Project A and implement ISpiroPdfAlex. This will give you the ability to call each of the 3 different versions through the same API.
After this, create a subfolder under Project A for each of the versions (so 3 subfolders total) - since Project A has no reference to any of the external assemblies, it cannot load them by itself - you'll have to manually load them when you need the right version. Since your external DLLs may have dependencies with the same name, they cannot all be in the same folder (as you wrote), this is why you need the subfolders.
At run-time when you need one of these versions, you can call Assembly.LoadFile to load a specific version of your assembly from the specified folder and then you can either use Activator.CreateInstance or dependency injection to create an instance of a class that implements your interface. Once you have the instance, you're free to call any of the functions and you'll get version-dependent behavior.
Edit:
OP mentioned in a comment that it's not his code that has the dependency on different versions of the PDF library but the other 3rd-party Spire libraries that his code depends on.
In this case, the 3rd-party code cannot be modified to support dynamic loading of assemblies and they already have a binary dependency. It's not possible to load different versions of the "same" assembly into the same process, especially that you mentioned that these versions are not even backward-compatible with each other.
The only solution I can think of in this situation is to break out all dependent functionality into separate console applications (one for each different version) and call those separate .exe-s through the command-line.
To pass information, you can either pass data directly on the command-line or through stdin. Alternatively, you can just pass the name of a temporary file that has all data necessary to do some processing. To get return data back from the console process, you can either read its stdout or use the same / different file.
This way your main process never loads any of these assemblies and has no dependency on them - each console application has a dependency on just one version so there's no collision.
I have a framework which contains several assemblies. Multiple assemblies was created due to logical separation of code. This framework is supposed to be distributed to developer as well as end user. Developer are supposed to use few of framework assemblies to develop their modules. But all other assemblies are required to run the modules. Out of several assemblies, I want only few assemblies could be added to project reference and restrict other from being added to developer project references. In other words, I want developer should not be able to use types contained in assemblies which are not meant for plugin development. What is the best way to do that? I want to avoid passing some object to constructor of each type in those assemblies and verify them.
Can I take advantage of AppDomain or anything similar to that, which identifies type is being created by main app or module. If it is not main app, then throw exception or don't initialize. Any change in architecture is suggested.
One option would be to make the types within the "restricted" assemblies internal instead of public, then add InternalsVisibleToAttribute within those restricted assemblies to allow access to them from the other "framework" assemblies.
That way the end developer can still add a reference to the "restricted" assemblies (and probably should do so, in order to make sure they're copied for deployment) but won't be able to use any of the types within those assemblies.
EDIT: Another alternative might be to use ILMerge to build one assembly at the end - so it's a real unit of deployment, even though you originally split it out for separation reasons.
Yet another alternative would be to merge everything into one project and rely on code review, namespaces and common sense to pick up separation violations.
You can make all of the types in the other assemblies internal to prevent them from being ued outside their defining assembly.
You can use the [InternalsVisibleTo] attribute to make them visible to your other assemblies.
I have an application that loads dlls dynamically. The application and the
dlls use a Functions.dll that can be a diferent version for the application an
for each dll, but in execution the application and the dlls all use the same
dll version (the one used by the EXE) and share the static variables...
How can i force them to use their own Functions.dll(n-version)?
-Details:
I tried loading the dlls by "Assembly
dll = Assembly.LoadFile(" and by
"Assembly dll=domaindll.Load("
In Functions.dll, al the methods and objects are Static
I use Functions.dll "statically" by referencing it throught VS in all
cases not dynamically
The dlls and Functions.dll are developed in C# too
-Folder Estructure:
Application:
Application.EXE
Functions.dll(version 1.2)
DLLS:
EXAMPLEDLL1:
EXAMPLEDLL1.DLL
Functions.dll(version 1.1)
EXAMPLEDLL2:
EXAMPLEDLL2.DLL
Functions.dll(version 1.0)
EXAMPLEDLL3:
EXAMPLEDLL3.DLL
Functions.dll(version 1.2)
You can enforce binding to a specific version of a DLL by strong-signing it. You can also try setting "Specific Version" to true on the reference properties, but as far as I'm aware that only affects compile-time binding and a different version can be loaded at runtime if the assembly isn't strong-signed.
This should get you started: Strong-Name Signing for Managed Applications
Be aware, though, that any types declared in this dll will not be type-equivalent to the same type in a different version of the assembly. For instance, if I declare a class called Foo in Functions.dll, then an instance of Foo from version 1.0 won't be the same type as an instance of Foo from version 1.1. As far as the CLR is concerned, these are completely different types.
If all you have are static functions in the assembly and no types are defined, then you should be OK. Otherwise you need to look into a different approach.
To be able to do that I think you'll have to load your (Example) DLLs into separate AppDomains. Making cross-AppDomain calls incurs a bit of a performance penalty, but that is kinda unavoidable in the scenario you highlight.
At the end I solved it renaming the Functions.dll to match the EXAMPLEDLL that uses it....Ex: Application.EXE-->FunctionsApplication.dll EXAMPLEDLL1.dll-->FunctionsEXAMPLEDLL1.dll Thanks for the answers anyway..
Postdata: In another case where I could sign correctly the dlls i think Adam Robinson answer would be the correct one(and jerryjvl the second anwser).