I have a visual studio solution.
I have many projects in the solution.
There is one main project which acts as the start up and uses other projects.
There is one project say "ProjectX". Its reference is added to main project.
The ProjectX references another .NET dll (say abc.dll) that isn't part of the solution.
Now this abc.dll should be copied to bin/debug folder of main project, but it isn't getting copied there. Why is it not getting copied, any known reasons ?
I found that if ProjectX referenced the abc.dll but didn't directly use any of the types DEFINED in abc.dll, then abc.dll would NOT be copied to the main output folder. (It would be copied to the ProjectX output folder, to make it extra-confusing.)
So, if you're not explicitly using any of the types from abc.dll anywhere in ProjectX, then put a dummy declaration somewhere in one of the files in ProjectX.
AbcDll.AnyClass dummy006; // this will be enough to cause the DLL to be copied
You don't need to do this for every class -- just once will be enough to make the DLL copy and everything work as expected.
Addendum: Note that this may work for debug mode, but NOT for release. See #nvirth's answer for details.
Just a sidenote to Overlord Zurg's answer.
I've added the dummy reference this way, and it worked in Debug mode:
public class DummyClass
{
private static void Dummy()
{
var dummy = typeof(AbcDll.AnyClass);
}
}
But in Release mode, the dependent dll still did not get copied.
This worked however:
public class DummyClass
{
private static void Dummy()
{
Action<Type> noop = _ => {};
var dummy = typeof(AbcDll.AnyClass);
noop(dummy);
}
}
This infomation actually costed me hours to figure out, so I thought I share it.
Yes, you'll need to set Copy Local to true. However, I'm pretty sure you'll also need to reference that assembly from the main project and set Copy Local to true as well - it doesn't just get copied from a dependent assembly.
You can get to the Copy Local property by clicking on the assembly under References and pressing F4.
It looks slick when you make it an assembly attribute
[AttributeUsage(AttributeTargets.Assembly)]
public class ForceAssemblyReference: Attribute
{
public ForceAssemblyReference(Type forcedType)
{
//not sure if these two lines are required since
//the type is passed to constructor as parameter,
//thus effectively being used
Action<Type> noop = _ => { };
noop(forcedType);
}
}
The usage will be:
[assembly: ForceAssemblyReference(typeof(AbcDll.AnyClass))]
Ran into this same issue. Background info: before building, I had added a new Project X to the solution. Project Y depended on Project X and Project A, B, C depended on Project Y.
Build errors were that Project A, B, C, Y, and X dlls could not be found.
Root cause was that newly created Project X targeted .NET 4.5 while the rest of the solution projects targeted .NET 4.5.1. Project X didn't build causing the rest of the Projects to not build either.
Make sure any newly added Projects target the same .NET version as the rest of the solution.
Not sure if this helps but for me, many times I reference a DLL (which automatically adds it to the bin folder of course). However that DLL might need additional DLLs (depending on what functions I'm using). I do NOT want to reference those in my Project because they just simply need to end up in the same folder as the DLL I am actually using.
I accomplish this in Visual Studio by "Adding an existing file". You should be able to add it anywhere except the Add_data folder. personally I just add it to the root.
Then change the properties of that file to ...
Build Action = None (having this set to something like Content actually copies the "root" version to the root, plus a copy in the Bin).
Copy to output folder = Copy if Newer (Basically puts it in the BIN folder only if it is missing, but doesn't do it after that)
When I publish.. my added DLL's only exists in the BIN folder and nowhere else in the Publish location (which is what I want).
You could also check to make sure the DLLs you're looking for aren't included in the GAC. I believe Visual Studio is being smart about not copying those files if it already exists in the GAC on the build machine.
I recently ran in this situation where I'd been testing an SSIS package that needed assemblies to exist in the GAC. I'd since forgotten that and was wondering why those DLLs weren't coming out during a build.
To check what's in the GAC (from a Visual Studio Developer Command Prompt):
gacutil -l
Or output to a file to make it easier to read:
gacutil -l > output.txt
notepad.exe output.txt
To remove an assembly:
gacutil -u MyProjectAssemblyName
I should also note, that once I removed the files from the GAC they were correctly output in the \bin directory after a build (Even for assemblies that were not directly referenced in the root project). This was on Visual Studio 2013 Update 5.
If you right Click the referenced assembly, you will see a property called Copy Local. If Copy Local is set to true, then the assembly should be included in the bin. However, there seams to be a problem with Visual studio, that sometimes it does not include the referenced dll in the bin folder... this is the workaround that worked for me:
In my case, it was the stupidest thing, caused by a default behavior of TFS/VS that I disagree with.
Since adding the dll as a reference to the main project did not work, I decided to add it as an "Existing Item", with Copy Local = Always. Even then the file was not there.
Turns out that, even though the file is present on the VS Solution and everything compiled both locally and on the server, VS/TFS did not add actually add the file to source control. It was not included on the "Pending Changes" at all. I had to manually go to the Source Control Explorer and explicitly click on the "Add items to folder" icon.
Stupid because I've been developing for 15 years in VS. I've run into this before, I just did not remember and somehow I missed it because everything still compiled because of the file being a regular reference, but the file that was added as Existing Item was not being copied because it did not exist on the source control server.
I hope this saves someone some time, since I lost 2 days of my life to this.
Issue:
Encountered with a similar issue for a NuGet package DLL (Newtonsoft.json.dll) where the build output doesn't include the referenced DLL. But the compilation goes thru fine.
Fix:
Go through your projects in a text editor and look for references with "Private" tags in them. Like True or False. “Private” is a synonym for “Copy Local.” Somewhere in the actions, MSBuild is taking to locate dependencies, it’s finding your dependency somewhere else and deciding not to copy it.
So, go through each .csproj/.vbproj file and remove the tags manually. Rebuild, and everything works in both Visual Studio and MSBuild. Once you’ve got that working, you can go back in and update the to where you think they need to be.
Reference:
https://www.paraesthesia.com/archive/2008/02/13/what-to-do-if-copy-local-works-in-vs-but.aspx/
Make sure that the dependent DLL used by you does not have target .NET Framework higher than the target .NET framework of your project's Application.
You can check this by selecting your project, then press ALT+ENTER, then select Application from left side and then select Target Framework of your project.
Suppose,
dependent DLL Target Framework = 4.0 and
Application DLL Target Framework = 3.5 then change this to 4.0
Thank you!
This is a slight tweak on nvirth's example
internal class DummyClass
{
private static void Dummy()
{
Noop(typeof(AbcDll.AnyClass));
}
private static void Noop(Type _) { }
}
I would do add it to Postbuild events to copy necessary libraries to the output directories. Something like XCopy pathtolibraries targetdirectory
You can find them on project properties -> Build Events.
TLDR; Visual Studio 2019 may simply need a restart.
I encountered this situation using projects based on Microsoft.NET.Sdk project.
<Project Sdk="Microsoft.NET.Sdk">
Specifically:
Project1: targets .netstandard2.1
references Microsoft.Extensions.Logging.Console via Nuget
Project2: targets .netstandard2.1
references Project1 via a Project reference
Project2Tests: targets .netcoreapp3.1
references Project2 via a Project reference
At test execution, I received the error messaging indicating that Microsoft.Extensions.Logging.Console could not be found, and it was indeed not in the output directory.
I decided to work around the issue by adding Microsoft.Extensions.Logging.Console to Project2, only to discover that Visual Studio's Nuget Manager did not list Microsoft.Extensions.Logging.Console as installed in Project1, despite it's presence in the Project1.csproj file.
A simple shut down and restart of Visual Studio resolved the problem without the need to add an extra reference. Perhaps this will save someone 45 minutes of lost productivity :-)
You may set both the main project and ProjectX's build output path to the same folder, then you can get all the dlls you need in that folder.
NO NEED FOR DUMMY IN CODE
Just :
add a Reference to the Executeable Project
or/and ensure that the reference in the executeable project has "Copy Local" set to TRUE (which was my "fault") is seems that this "overwrote" the setting in the base referenced library-project...
Other than the common ones above, I had a multi-project solution to publish. Apparently some files target different frameworks.
So my solution: Properties > Specific Version (False)
Add the DLL as an existing item to one of the projects and it should be sorted
VS2019 V16.6.3
For me the problem was somehow the main .proj file ended up with an entry like this for the project whose DLL wasn't getting copied to the parent project bin folder:
<ProjectReference Include="Project B.csproj">
<Project>{blah blah}</Project>
<Name>Project B</Name>
<Private>True</Private>
</ProjectReference>
I manually deleted the line <Private>True</Private> and the DLL was then copied to the main project bin folder on every build of the main project.
If you go to the reference of the problem project in the references folder of the main project, click it and view properties there is a "Copy Local" setting. The private tag equates to this setting, but for me for some reason changing copy local had no effect on the private tag in the .proj file.
Annoyingly I didn't change the copy local value for the reference, no idea how it got set that way and another day wasted tracking down a stupid problem with VS.
Thanks to all the other answers that helped zone me in on the cause.
HTH
I had a similar issue in which a DLL I had included in the project as content and 'Copy always' set, wasn't being copied to the bin folder. I solved this by adding a dependentAssembly reference to the DLL in the app.config.
I'm working on a C# project that is nearing release. As part of this, I have started building the project and testing it on another machine. This has revealed some odd problems. My biggest concern, though, is that my project is failing to run. I can do some basic things, but when I try to use my projects primary functionality it crashes. Using Visual Studio, I was able to determine the exception that was causing the crash.
Essentially, I'm getting a FileNotFoundException on the dll that contains most of my project's functional code. I'm not sure if I've made an error in adding the dll to my project, or if there's a problem in one of the files in the dll.
The dll was added as a reference using the Project -> Add Reerences feature of the user interface.
The dll contains three files which contain absolute file paths (these are for #import statements). Example follows.
#import "C:\Users\Me\Documents\Projects\MyProject\Delegates\bin\MyDelegate.tlb" raw_interfaces_only
My hang up is I'm not exactly sure what I'm doing wrong here. I suspect that those import statements are causing problems, but I'm not exactly sure how to fix them if they in fact are the problem. This is my first c#/c++ project so any help would be appreciated.
Adding the dll as a reference DOES NOT include the dll with your project--you are simply telling your project to use the library for your code. The dll will need to be installed on all computers that run your application, for your application to use the dll.
If the dll also uses three files (as you specified), then those files must also be included, and be installed in the expected path.
Presuming you have redistribution rights on the dll you mention, you can include the dll in your project. Be sure to set the "copy" property as "copy always" or "copy if newer" and change the reference to use the copy that ends up in you bin folder. Then you only need to be sure to include that dll and install it in the same folder as your application.
I'm adding my dll file to my reference and set Copy local to true
Everything is OK and after I build application, my dll added to output folder
Now my question is how do Ι change the local path?
For example:
my application path is C:\myproject, I want to put dll into C:\myproject\libs
How can I set dll path to {applicatonpath}\libs NOT {applicationpath} ?
When you compile you project, visual studio will put everything that has been compiled and set to copy locally to the "output folder", which depends on your current compile configuration. If you are compiling in Debug mode then this folder will be:
c:\your_solution_path\your_project_path\bin\Debug
If you use Release mode, it will be:
c:\your_solution_path\your_project_path\bin\Release
However, sometimes we reference a lot of assemblies (DLLs if you will) and those assemblies have dependencies of their own. In order to make everything "point and click" for our convenience, we must tell visual studio how we would like it to act for a particular project build.
So, as TotPeRo said, you should go do project properties and use the functionality of Pre-build and Post-build events. As the name suggests, Pre-Build happens before the actual build, while Post-Build takes place immediately after it. Please refer these links for further information: link1 and link2.
Lets assume the following scenario:
You have one solution.
that solution holds 2 projects (let's call them Project A and Project B). Project A is the actual GUI. Project B is just a helper project, that compiles into a DLL.
Let's say, that project B is doing some heavy matrix calculations, so you also have to include some MatLab libraries. NOTE: only Project B uses these libraries.
Project A references project B so that you can use the calculated information from B and show it in gui in A.
In order to compile this, the compiler is smart enough to determine, that Project B should be compiled first. If everything checks, the project is compiled into ProjectB.dll. Then, the compiler proceeds to compile Project A. It check all the dependencies and finds out, that you have already compiled Project B (which is a dependency for Project A) and that it can continue. Everything is then copied to the output folder (bin/Debug or bin/release) and should be in working order.
However, during runtime, something goes wrong and the application crashes. You find out, that Project B does not have the appropriate library to work with (namely MatLab libraries). And then you conclude, that MatLab should be included in the bin/debug (or bin/release) folder at compile-time. Since the MatLab library is a dependency library for Project B but not for Project A, it does not get copied and hence the exception. You can mitigate this behavior with the aforementioned Pre and Post-Build events. You can tell the Visual Studio that you want it to manually copy MatLab.dll to the output folder when it is doing a compile. This comes super handy when you come into situations like these. Build events can also trigger a lot of other things so be sure to check it out. I'm using this a lot and it's a time saver at least.
in the Visual Studio you can go Project > [project name] Properties > Reference Path
change the path/create folder or else you want
First make folder lib new project source code then use relative address
in post-build event on visual studio go to properties in your project and add this:
copy "c:\pathtolibrary\bin\debug\namelibrary.dll" "$(SolutionDir)\bin\Debug\libs"
I have a C# project which references a DLL (call it external DLL) which comes with another application. When I build my project, due to the reference, the external DLL gets automatically added to my project output. And when I run my project it loads the external DLL from my project folder.
The other application, which the external DLL belongs to, is developed by another team and the DLL is regularly updated. I don't want to package their DLL with my project. Instead I would like to have my project load their DLL when executed -- rather than pick the DLL copy from my project's folder.
Now I know that this is possible through reflection. I know that I can do an "Assembly.Load" and pick the DLL. But because I use the types from the external DLL all through my code, I would like the code to be statically type checked.
Here's what I would like:
Be able to compile my project by referencing the external DLL and thus get static type checking.
When the project is run, the external DLL is picked up from the other application's folder and not the copy of the DLL which is in my project's output folder.
Is there any way to solve this problem? Is there some middle ground between adding a reference and using reflection?
The most immediete solution to your problem is to change the properties of the reference. There is a setting called Copy Local. Set that to false and it'll stop copying the DLL to your project's output. You can access the properties of the reference by expanding the references folder in your solution, right-clicking on the reference in question, and clicking properties to open the properties pane.
The fact that Visual Studio copies the DLL to your project's output folder at build time doesn't really matter to the .Net Framework at runtime. All that matters is that the assemblies you reference are available to the framework either in the paths it searches or in the global assembly cache.
My Current structure is as follows
/Project Name/
file1.cs
file2.cs
project.sln
Libraries/
I know the common answer is to put a Libraries folder within the /Project Name/ folder as shown above. Is this correct?
If so, do I need to do anything special when adding the references in my project? What do I need to set for the "Copy Local" option? Thanks.
For an answer to the first question, see Location of Third Party Dll's in Version Control for .NET Project.
For your second question: nothing special needs to be done; adding a Reference in Visual Studio (using the Browse tab) will automatically set up the assembly DLL to be copied to the output folder.