C# dll not updating across projects - c#

I've got a C# project in visual studio that is building a DLL, and another console project which includes the first as a reference. These are both in the same solution.
The trouble is when I add methods to the DLL, then rebuild the console project doesn't seem to pick them up.
For example, in the DLL I have a class Converters. If I add a method
public static void test() {}
it just doesnt' show up in the console app at all. Intellisense doesn't autocomplete it, and if I manually type it in it gives a compiler error.
If I go in and delete the dll files then rebuild that works (or better yet, delete the bin and obj directories) but that seems rather drastic.
I'm sure this is a basic error, but I can't seem to find the solution after some googling.


How are you adding the reference? As a project reference or by browsing to the DLL? If you're using the latter then it will copy it locally to the bin directory of your console app and won't refresh it unless you manually delete it. If you add it as a project reference it will copy it as and when it needs to.


The exact thing happened to me once on a project - it turned out the build command wasn't configured to build these DLLs.
Check Build - Configuration Manager, and make sure the project is checked:
(Image from msdb - Setting the Build Configuration)


close Project visualStudio and
rebuild again your dll (other project visualStudio)


One of the things to note is the Target Framework of the Projects, if you compile your Project A with target framework different then that of Project B and it is referencing the dlls of Project A you may run into this kind of trouble. So, make sure that the target framework for both Projects is same.


Check that you don't have the ddl inside the bin folder of your project. Whilst I was adding the reference by browsing for the dll, I had forgotten that I manually copy pasted a version into that folder. No matter how many times I cleaned and rebuilt, it didn't seem to update.
Deleting that dll and re-referencing fixed the issue.


Change the reference to the dll to the Project, instead of the output.


This is certainly unexpected behavior. It sounds like the reference between the two projects is broken in some way. Two issues come to mind.
Possible problem with the reference. Try deleting the reference in solution explorer and readding the reference and seeing if that fixes things. When you re-add make sure it's a project reference and not a file reference.
It's possible that the time stamps on the files in your project are off. See if they are in the future.


check the folder which contains the reference. does it contain a refresh file with a relative path in it? if so, and if assembly names in the location pointed to by the relative path are common with those in of (project) references which should auto update, then these references no longer auto update! what you end up is a static reference to the assemblies present in the relative path contained in the refresh file.
you may also have to delete the projectreferences key in the sln file and add references afresh


I hate to beat a dead SO question but 8 years after the original question and none of the above solving the issue for me, my problem was in VS2013, but to solve it I simply removed and re-added the reference to the DLL in the project that invokes it.
I hope this helps some people in the newer VS realm having the same issue.

Related

VS solution's props and target setting not copying files to output directory [duplicate]

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.

One of the assembly gets deleted from my solution everytime I build

I am using VS2012 and I am seeing weird problem. I added a new project into my solution and that project was working all fine until now.
Now, Everytime I build/re-build the solution, i am seeing reference errors from different projects which are using that particular reference. I checked the bin/debug folder and assembly is not there.
Surprisingly enough, when I build that particular project by it self, it builds successfully and produces the assembly into bin/debug folder.
Now, it works when built alone but does not work when build in solution. And when I build entire solution, something causes the .dll file to be deleted somehow to cause all the references to break.
I have done following things so far:
Made sure this project is second one to be built in entire solution
Went through all the projects which I are depending on this project and added the dependency manually.
Any ideas on how can I solve this issue?

If the referencing project and the referenced project are both in the same Visual Studio solution then it is generally considered a best practice to use project references rather than assembly references. This ensures that build dependency orders are maintained automatically and helps prevent you from accidentally creating circular references.
Assembly references should only be used when you cannot add the project that created the assembly to your solution. When you do use assembly references (which I don't recommend in this case) you should put the assemblies into a common folder outside of your bin\debug folder structure to ensure you don't accidentally delete the file when, for example, you do a Clean operation.

vs2010 - reference .exe not working

I've got a project (project A)in vs2010 (c#) that I want to reference another project (.exe) (project B) that I created. Project A is a quick, down & dirty util that I will only use once but I need all the function calls and db calls from project B, so rather than cut, copy, pasting from one to another, I thought I could just reference project B in my references. I am able to point to the .exe and in code i can use it, but when I compile it, it complains about not being able to see it (the infamous "are you missing a using directive or assembly reference?" error).
Does anyone know how I can do this?

Most probably, also it's hard to say, you have .NET Framework version conflict. One of your projects has .NET Framework version which is not compatible with other.
Check in project properties of both of them the version of the framework.
Make them the same
Recompile both of them
and most probably the trouble will gone.
Hope this helps.

Make sure the namespace of classes you want to use from project A is included in the files in your project B in a using directive:
using projA.ExampleNamespace;

I have the same problem. When I first added the reference all worked fine. But some time later after a rebuild there were errors and the classes and namespaces of "project A" were not longer recognized. Removing and re-adding the reference solved the problem immediately (without rebuiling or anything). There were no errors in other code and all DLLs and EXEs were build correctly. Build Order and Build Dependency settings were also correct. Seems to be a strange bug in Visual Studio (I use 2013 Professional).
I also checked how the reference was set in csproj file. The csproj file didn't change at all after removing and re-adding the reference. Neither did the sln file.
Maybe it's some strange caching behavior. But as I used "Rebuild All" which cleans up temporary files imho, this shouldn't happen. Even restarting VS or the PC didn't help.

Amazon Mechanical Turk DLL references keep disappearing during compilation

I've downloaded and compiled Amazon's .NET SDK for Mechanical Turk, producing two DLLs: Amazon.WebServices.MechanicalTurk.dll and Amazon.WebServices.MechanicalTurk.Domain.dll .
I then created a new WPF project and added the two DLLs as references. When I create objects from their space, Intellisense has no trouble browsing the assemblies- I can see the classes inside.
When I compile, however, I get an "type not found" error from the compiler. Intellisense no longer works for the Amazon namespace, and the DLLs have vanished from the Object Browser window inside Visual Studio, though they're still listed as references in Solution Explorer.
What's going on? I think I'm missing something obvious. I can see, for example, MTConfig, but when I try to instantiate it, it fails and I need to re-add the DLLs to try again.
Thanks!

How have you added the references? Did you copy the DLLs into your new project's output folder and add references to them there? I can imagine that giving the behaviour you describe, if VS wipes the output folder before a build. If that's what's happening, simply move the DLLs to a different directory (I typically create a "lib" directory) and point the reference there.

What I did to solve this same problem was to recompile the DLLs changing the .NET version from 2.0 to 4.0 in the project properties. Not sure why that works, but in my case it solved the issue.

Project reference path in source control?

during development of our application we use a branching structure and while we are developing another team is using earlier builds of our software to create content with it.
To facilitate easy swapping between builds and teams I was hoping to use empty Hintpaths in the content projects' csproj files so that they can use our GAC installed assemblies to build against and in the meantime add a reference path to the projects for our use during development and test cycles where we don't want any assemblies installed in the GAC.
However, it seems reference paths are not stored in the csproj file and thus don't get sourcecontrolled. Since there will be extensive branching it would be less than ideal to have to set all reference paths again when a developer pulls another branch from sourcecontrol.
I've been searching for a bit now and can't seem to find ways to do this. Anybody know of a way to force the reference path in and out of sourcecontrol?
We're talking Visual Studio 2008 and TFS 2008 here.
Cheers,
Anton.

Ok, I seem to be a little clearer in the head after a good night's sleep, took the logical step, namely investigate where exactly the information was stored and how. It turned out the information was stored in the .user file for the project in the project's folder and as it turens out this file contains mbsuild xml.
I then did what I wanted as follows:
Create the Reference path as I required it to facilitate both scenarios without any work.
Browse to the Project's .user file
Copy the PropertyGroup containing the ReferencePath
Paste the PropertyGroup in all the necessary Projects' .csproj xml.
Reload and build.
Done.

The references are stored in the *.csproj file. The nodes are ItemGroup/Reference...
Thomas

This is pretty simple--we do this in our shop.
First, in the Workspace (using Windows Explorer, browse to the Solution folder), create a folder. We name it "Referenced Assemblies". In here, drop all your DLLs.
Now, in the Solution, add a new folder to match the one created in Windows Explorer. Into that folder, add all the DLLs you just dropped in.
Finally, in each project, set up your references to use the DLLs that were added to the solution.
Now your project references DLLs that are part of the solution, so that when the build runs, it will grab the DLL from Source Control to generate the build.
Also, I'd recommend not using the GAC at all if you can avoid it. In my experience, reference behavior is strange. It seems references go first to the GAC, then to the DLL in the local folder, meaning that if the DLL is updated, the one in the GAC is used instead of the DLL in the local folder (which is likely the updated one).

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