Ever since I've been using the (relatively) new .NET Standard Library project type in Visual Studio, I've been having some problems getting a complete set of DLL files that are required by my project.
The problem is usually limited to 3rd-party libraries which I reference as NuGet packages. I've noticed that these don't get copied to the output folder of my project when I build it. This didn't use to be the case in classic project types.
While I can appreciate the de-cluttering effect that this change has brought for .NET Standard projects, I'm now faced with a problem. I sometimes absolutely need to be able to get the entire list of all files that my project depends on!
I have several different cases, where I might require this list for one reason or another, but the one I believe is most crucial for me, is when I want to gather these files from the csproj itself, right after it's built. In there, I have a custom MSBuild <Target> which should take all the files from the output dir and zip them together for distribution. The problem is, I'm missing all the files that come from NuGet dependencies, because they're not there!
How can I solve this in a general (i.e. not project-specific) way?
UPDATE
There's this deps.json file that contains basically all I'm after and then some. It's just a matter of extracting the relevant information and find the files in the local NuGet cache. But that would involve writing a specialized app and calling it from my target. Before I start writing one myself... Is there something like this already out there somewhere?
I followed this answer and it sort of works.
The suggested thing was to include the following into my csproj:
<CopyLocalLockFileAssemblies>true</CopyLocalLockFileAssemblies>
My main concern is that it also outputs some other DLLs from the framework (such as System.Memory.dll and System.Buffers.dll, among others), which I didn't expect. But maybe that's a good thing. They do seem to be dependencies, just not direct ones. I'll see how it plays out.
If it turns out ok, my only wish would be that this directive was more prominently displayed in project settings (as a simple checkbox, maybe?) so I wouldn't have to hunt the web to find it.
How do I build sample code, split into folders in a repo, from a class or tutorial, in Visual Studio?
So - I'm pretty much a noob at C#, I've gone through a lot of tutorials and browsed through some large C# projects from work and built them, and done some other minor things. I'm going through a course on writing testable code on Pluralsight. He has a public Github repo for the code examples, writing-testable-code. I connected to the repo and downloaded it okay into a local Git repo. I was able to download all the packages from NuGet and they are all showing as the version he used (a few have updates, but I figured updating might break things).
I can't figure out how to run this code, build it, or run the tests in it.
What I tried so far
My issue is - I open the solution, and there are a bunch of files and folders - each module/chapter is split into folders (i.e. Module1/Easy, Module1/Hard, Module2/Easy, etc.). I want to build the Module1/Easy folder, including unit test examples, and run the tests.
When reviewing Module1/Easy, it has 3 files that should build okay - the program.cs has a main() and looks like a console app, the Calculator.cs has a simple class, and the CalculatorTests.cs has unit tests built for Nunit. The solution has NUnit, Castle.core, and things from later modules (Moq, AutoMoq, Unity, Ninject, etc.). It didn't seem to have a VS runner, so I added Nunit3TestAdapter - the guy in the course has resharper installed, which I don't, and he was using the Resharper test runner, which would explain why he didn't include it.
I tried setting the "Module1/Easy/Project.cs" file the "Set as Startup Item", since it has a main and looks setup as a console app. However, running it (the "Start" button turned into a "Program.cs" button), it fails saying it can't run a dll. The tests aren't showing up in the Test Explorer like some other small projects I've built from examples.
What's the right way to do this?
I'm not sure where to go from here. On the Build menu is only a "Build Solution" and one about Code Analysis - I'm used to a lot more options here. It feels like I have to turn this folder into a project, maybe? I can always reinstall the packages - but what is the best solution here?
I've run into this before on other book, tutorial, or class repos, but finally decided to figure out how to get this one working. I appreciate any help!
Notes
I'm running Visual Studio Community 2017 at the moment.
I can post some of the files, but the repo is publically available, and not sure exactly what to post to help.
Progress from comments and answers
Per Biker-Dude's answer, I switched the project to build a console app rather than a dll, and now I get a compile-time error for having multiple entry points (i.e. every module and sub folder has its own Main() function and should probably be a separate project).
After #1, I removed all folders but one from the solution, it will then compile, run the tests, etc. - but I eventually want to be able to at least separately compile every sub-folder - what's the best way?
The problem must be that the project must have the output type set to class libraries. Browse through the solution tree and:
Select your class's project> right click > Properties > Application >
Output Type > Console Application/ Windows Application.
This should fix it, if the other things are set up properly.
With the help of BikerDude's answer and stijn's comments, I was eventually able to play around with this and get some things working.
First of all, don't try to exclude any folders in this situation, that will just make things worse! They will still be in your underlying folder/repo, just won't be showing up in your solution anywhere, and you won't be able to create a new folder with the same name (weird decision...). And you'll have to add them back in as individual files - I think.
The best solution (so far)
The best solution seems to be:
Create a new project for each buildable set of files in the solution (in my case, at least one project per "module" folder). I used the ".Net framework console app" project type (right click on the solution, use Add/New Project) to get things to work, but this would depend on the particular course or tutorial repo you downloaded.
Move the folder or sub-folder that has the files you want to build out of the main solution and into the new project - you can click and drag to move it.
Visual Studio will make an empty, pre-formatted file in your project that you likely have to delete - for .Net apps, this is the "Program.cs" file in C#. For one of my folders this file already existed, and I had to delete the new one in order to build. Another folder from a different module was setup more like a library and couldn't build standalone, but this procedure did get me to being able to build the files and that allowed the unit tests to show up in the test explorer and run the tests successfully (which was the main point of that module).
Go to the solution and right-click and choose "Manage Nuget Packages for Solution". As long as all the packages are installed for the main solution, then they will all show up in the list of Installed Packages (you might need to click on the "Installed" tab). You can click on each package in turn, then on the right you can checkmark the new project, and the "Install" button should be available - click it. Repeat for all the packages to install them all. Note that you can cut out some repetition here if you create all the projects you need first, then you can install all of them at the same time in this step (i.e. checkmark all the new projects at once instead of reopening the package manager each time).
You might have to fix the NameSpace - it should be consistent within the files/folders you transferred from the original solution, but if you add any new files to play with things, the Namespace for it will likely not match, and to see classes, etc. in the original files, you'll have to update your Namespace on the new files.
Per BikerDude's answer - After transferring everything to new projects, if you keep anything in the original project that came with the solution, it might not be trying to build the right type of item. You may be able to fix that by right-clicking the project, selecting properties, and adjusting the "output type", but it may not have the options you need. If it doesn't, just create a new project with the right type and transfer the files as above.
After following the above steps, I was able to build each new project I created, using the original files from folders that I moved. Mainly I just needed to build, which enabled all the unit tests that this tutorial/class was focused on, but this allowed me to build the console apps as well, when present.
Thanks for the help from all in pointing me in the right direction!
After a struggle with creating a database (first with an entity framework, after without), we have a database (and an EntityModel_HFFContext file we don't use, it's not connected). Normal work proceeded, and I installed a NuGet-package for an MVC sitemap.
From that moment, the project worked fine, but after a couple of days two warnings came up about two files missing: "The parent file, 'EntityModel_HFF.tt', for file 'locatie.cs' cannot be found in the project file." ("HFF" is the project name in here) and then those multiplied themselves into errors: "Source file 'locatie.cs' cannot be found" in a CSC file I cannot find.
These two files ('locatie.cs' and 'klant.cs') are not in any view, but somehow they are displayed outside all folders, saying they do not excist (see this screencapture). I have tried to delete those files manually, but that did not have any success. I have tried some other ways too, but that resulted into the complete deletion of the database, so now I am somewhat desperate.
I have no idea where to look and what to do, to get rid of these two files (or probably references to these files, since we don't use them at all), so I don't have these errors anymore. Has anyone of you have a clue of where I need to look (e.g. where this CSC file is) and what I need to adjust to fix this?
Maybe it can be useful to know I use Visual Studio 2013.
Update
I fixed the errors by unloading the project, editing the .csproj file and commenting out
<Compile Include="klant.cs">
<DependentUpon>EntityModel_HFF.tt</DependentUpon>
</Compile>
(and the other one too). Now these errors are gone - is this a safe way to do this?
The reason why you get the error is because when you deleted the locatie.cs and klant.cs file, you didn't remove them from the project solution itself, therefore, Visual Studio is expecting the file to be part of the project but is unable to find them, which explains the yellow warning signs.
Like what you said, all you have to do is to remove the files from the solution as they no longer exists. So yes, it is safe to comment out that portion in the .csproj file.
Although, I would like to mention that you didn't have to go to that much trouble, all you had to do was to delete the file in your solution in Visual Studio, since they no longer exists anyway.
I am dealing with a really huge work such that we have a solution and there are about 100-120 projects under it. Once I was trying to launch it but it took extra long I had to cancel it. Now a number of dll files under bin folder are lost, and most of those files were created by fellow projects under the solution.
Now I cannot rebuild/build.
Till now:
-have cleaned and tried to rebuild the solutions and project folders(each folder, is directly under solution contains like 5-6 projects) one by one. I also tried rebuilding projects one by one but it took too long and was useless.
-cleaned the solution, restarted visual studio(even the computer itself), but did not worked.
-cleared the Temporary ASP.NET Files under C:\Windows\microsoft\\ TEmp... and failed to relaunch again.
-Also tried to manually add missing references to projects but since there are over 100 projects it is not useful and will not work.
Any help will be appreciated greatly.
Thank you for your time.
try everything...(in order of a little to a lot of time wasted)
Do you have bad code? Fix that first.
Clean Solution & Restart Visual Studio
Remove / Add References
Check your build order w/ larger projects and verify
Manually rebuild sub-projects
Manually copy dlls between projects into associated bin folders
Go get some coffee, play some pinball and come back tomorrow...you may think of something else in the meanwhile.
I've been there before, it is a painful process. After you do what Vignesh told you, or while you do that, you can also use Dependency Walker to help figure out which dependencies are missing. This tool from the old days is still available for free and has helped a poor soul many times over. The main download page is dependencywalker dot com.
An additional tool to use is CheckAsm. Simplified, CheckAsm is a dependency walker for .NET.
It shows all .NET assembly references for any of your .NET assemblies. This tool is located at amberfish dot net. (They have an evaluation version which is free.)
I wish you well.
We decided to delete the current solution and get it back from TFS and it resolved our problem.
I have stumbled into an issue that is really annoying.
When I debug my software, everything runs OK, but if I hit a breakpoint and edit the code, when I try to continue running I get an error:
Metadata file 'XYZ' could not be found
After looking around for a while, I found some a similar issues, but they were all regarding a build failure, which is not my case (this happens only after edit-continue).
What I have tried so far:
My code is compiling and running.
I cleaned the solution and restarted VS.
I made sure that the missing file's project is being build for the configuration I am running (in configuration manager).
I manually built the missing file's project.
Some extra info:
It does not matter what I change, still get the same error (the change is not related to the missing file).
This happens also when I pause and continue (not only breakpoints)
I am running the project using a custom configuration (configuration manager...). When I run it using the default Debug configuration the error does not occur.
Any ideas?
Eventually what solved the issue was:
Clean every project individually (Right click> Clean).
Rebuild every project individually (Right click> Rebuild).
Rebuild the startup project.
I guess for some reason, just cleaning the solution had a different effect than specifically cleaning every project individually.
Edit:
As per #maplemale comment, It seems that sometimes removing and re-adding each reference is also required.
Update 2019:
This question got a lot of traffic in the past, but it seems that since VS 2017 was released, it got much less attention.
So another suggestion would be - Update to a newer version of VS (>= 2017) and among other new features this issue will also be solved
As far as I can tell, this happens when the project dependencies gets messed up for whatever reason (whilst all the inter-project references are still intact). For many cases, it is NOT a code issue. And for those who have more than a few projects, going through them one at a time is NOT acceptable.
It's easy to reset project dependencies -
Select all projects and right click unload
Select all projects and right click reload
Rebuild solution
For those who have an issue in their code or some other issue that's causing this problem you'll obviously have to solve that issue first.
One possible reason could be you have upgraded the some of your projects (in the solution) to higher version e.g. from .NET 4.0 to 4.5 This happened in my case when I opened the solution in VS 2013 (originally created using VS 2010 and .NET 4.0). When I opened in VS 2013 my C++ project got updated to .NET 4.5 and I started to see the problem.
Generally this kind of error comes with human mistakes like if we change the namespace in some improper way, or changing folder names from explorer for current project etc, where compiler is unable to detect sometimes.
I came across the same error, to resolve which I tried few steps. Please follow all the steps :
Clean whole Solution
Right Click on every Project in your solution , Go to Properties and make your Default namespace as well as Default assembly name same as in your code (i.e namespace before class name)
Check Folder names for each project by going through the explorer(Where your project solution is). If not matching with your project names, make it similar (Like step 2) to them.
Remove all your references from each project relevant to another of same solution, and add it again.
In Your Project Solution folder, you will find Visual c# Project file. Right click and open with Notepad. In your initial lines you would find for lines for every project like below:
Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "**Client**", "**Client** \ **Client**.csproj", "{4503E259-0E3B-414A-9074-F251684322A5}"
EndProject
Check again Foldernames (I have highlighted in BOLD) and make it similar to what you did in step 2.
Clean the whole solution again
Build The Solution (If doesn't work try building individual after cleaning again)
Make sure all your dependent projects are using the same .Net Framework version. I had the same issue caused by a dependent project using 4.5.1, while all others were using 4.5. Changing the project from 4.5.1 to 4.5 and rebuilding my solution fixed this issue for me.
XYZ couldn't be found because is not built yet....
Right click on the solution and check Project Dependencies, the Project Build Order should also change according to the dependencies that have been set.
The only thing that worked for me was to delete the Solution User Options (.suo) file. Note that, this is a hidden file.
To locate this file, close your Virsual studio and search for .suo from the file explorer within your project.
PS: a new .suo file will be created again when you rebuild your project and hopefully this newly created one wont give you issues.
I hope that helps someone get rid of this anoying error :).
I had this problem for days! I tried all the stuff above, but the problem kept coming back. When this message is shown it can have the meaning of "one or more projects in your solution did not compile cleanly" thus the metadata for the file was never written. But in my case, I didn't see any of the other compiler errors!!! I kept working at trying to compile each solution manually, and only after getting VS2012 to actually reveal some compiler errors I hadn't seen previously, this problem vanished.
I fooled around with build orders, no build orders, referencing debug dlls (which were manually compiled)... NOTHING seemed to work, until I found these errors which did not show up when compiling the entire solution!!!!
Sometimes, it seems, when compiling, that the compiler will exit on some errors... I've seen this in the past where after fixing issues, subsequent compiles show NEW errors. I don't know why it happens and it's somewhat rare for me to have these issues. However, when you do have them like this, it's a real pain in trying to find out what's going on. Good Luck!
Well, my answer is not just the summary of all the solutions, but it offers more than that.
Section (1):
In general solutions:
I had 4 errors of this kind (‘metadata file could not be found’) along with 1 error saying 'Source File Could Not Be Opened (‘Unspecified error ‘)'.
I tried to get rid of ‘metadata file could not be found’ error. For that, I read many posts, blogs etc and found these solutions may be effective (summarizing them over here):
Restart VS and try building again.
Go to 'Solution Explorer'. Right click on Solution. Go to Properties. Go to 'Configuration Manager'. Check if the checkboxes under 'Build' are checked or not. If any or all of them are unchecked, then check them and try building again.
If the above solution(s) do not work, then follow sequence mentioned in step 2 above, and even if all the checkboxes are checked, uncheck them, check again and try to build again.
Build Order and Project Dependencies:
Go to 'Solution Explorer'. Right click on Solution. Go to 'Project Dependencies...'. You will see 2 tabs: 'Dependencies' and 'Build Order'. This build order is the one in which solution builds. Check the project dependencies and the build order to verify if some project (say 'project1') which is dependent on other (say 'project2') is trying to build before that one (project2). This might be the cause for the error.
Check the path of the missing .dll:
Check the path of the missing .dll. If the path contains space or any other invalid path character, remove it and try building again.
If this is the cause, then adjust the build order.
Are you using a database code generation tool like SQLMETAL in your project?
If so, you may be facing a pluralized to unpluralized transition issue.
In my case, I have noted that some old pluralized (*) table names (upon which SQLMETAL adds, by default, an "s" letter at the end) table references to classes generated by SQLMETAL.
Since, I have recently disabled Pluralization of names, after regerating some database related classes, some of them lost their "s" prefix. Therefore, all references to affected table classes became invalid. For this reason, I have several compilation errors like the following:
'xxxx' does not contain a definition for 'TableNames' and no extension method 'TableNames' accepting a first argument of type 'yyyy' could be found (are you missing a using directive or an assembly reference?)
As you know, I takes only on error to prevent an assembly from compiling. And that is the missing assemply is linkable to dependent assemblies, causing the original "Metadata file 'XYZ' could not be found"
After fixing affected class tables references manually to their current names (unpluralized), I was finnaly able to get my project back to life!
(*) If option Visual Studio > Tools menu > Options > Database Tools > O/R Designer > Pluralization of names is enabled, some SQLMETALl code generator will add an "s" letter at the end of some generated table classes, although table has no "s" suffix on target database. For further information, please refer to http://msdn.microsoft.com/en-us/library/bb386987(v=vs.110).aspx
Hope it helps!
I had this error come up. I followed all of the solutions here but nothing worked. I was using Visual Studio 2013 Professional. I couldn't get the individual project rebuilds to work and I finally figured out there was a circular dependency in my references. Visual Studio does a pretty good job normally of warning you if you are adding a reference to something that references back, but for some reason it didn't in this instance. I added a reference to a project that referenced the project I was working on - and it accepted it. VS bug perhaps?
My 5 cents.
This problem started after a solution wide clean.
I managed to get the problem to go away by setting the Active Solution configuration in: Build -> Configuration manager to release. Then build and set it back to debug again. The build succeeded after that.
Close VS, locate and remove the 'packages' folder from outside of visual studio. Restart VS and build -> all dependencies are reinstalled
Visual Studio 2019 Community 16.3.10
I had similar issue with Release build. Debug build was compiling without any issues.
Turns out that the problem was caused by OneDrive. Most likely one could experience similar issues with any backed-up drive or cloud service.
I cleaned everything as per Avi Turner's great answer.
In addition, I manually deleted the \obj\Release -folder from my OneDrive folder and also logged to OneDrive with a browser and deleted the folder there also to prevent OneDrive from loading the cloud version back when compiling.
After that rebuilt and everything worked as should.
this happens because of the difference of names in the folder name and namespace name. If u create a namespace in a certain name , and later you rename it the namespace will have the old name itself. And the compilation will take the old path to find the .dll and .exe file . To avoid this open the .csproj file of each namespace with a text file , and find the old path in the file.
remove this, clean and rebuild the solution. This worked for me. I spent an entire day working on this problem.
I had this and managed to fix it using this SO answer:
Metadata file '.dll' could not be found
I had to uncheck all of the boxes, click Apply, reenable all of the checkboxes and then click apply again, but it fixed the problem.
I just ran into this issue and after an hour of screwing around realized I had added an aspx file to my product that had the same name as one of my Linq-To-Sql classes.
Class and Page where "Queue".
Changed the page to QueueMgr.aspx and everything built just fine.
For a new build, it could be that some dependencies aren't installed. For me it was Crystal Reports.
It happens when one project dll is failing and that is referenced by number of projects. So first fix it and then Build individuals.
I ve had this problem and it has started after importing our solution to TFS as a new project.I came across this topic and found a quick solution with some inspiration from your answers.
All i needed to do is to rebuild the project thats supposedly lost its metadata file and voila , problem solved.
There's also one another silly reason which you should check with patience... as it occurred to me after wasting 4hours searching for answers:
The story to me was that I accidentally changed a small line of code among thousands of c# class files and then trying to rebuild the solution. As you could imagine, I ended up with 40+ meta data file missing errors and with 1 compilation error among them -- which I didn't check carefully, purely thinking all errors were the same!
after 4 hours searching and then accidentally double checking my error list, I found that silly code error, fixed it, compiled, and then error disappeared.
Not a good answer to your problem, but do hope my case wasn't same to yours.
I had the same problem. In my case I had by mistake I had set all the projects apart from the project with the main method as console application.
To resolve I went to every project other than the one with main function and right click> properites > output type > class library
it was happened to me because I've a strange clash in the namespaces:
I had
AssemblyA
with namespace
AssemblyA.ParentNamespace
witch defines ClassA
and in the same assembly another namespace with name
AssemblyA.ParentNamespace.ChildNamespace
witch defines a different ClassA (but with the same name)
I had then in AssemblyA.ParentNamespace IInterfaceB witch had a method that in the beginning returns IEnumerable and a ClassB witch implements IInterfaceB
I had later modified the method in ClassB to return IEnumerable but I've forgot to update the IInterfaceB definition, so the method there was still returning IEnumerable
the fun fact was that the solution still complile if I did a rebuild all, but the tests witch refers AssemblyA didsn't work and returns the "Metadata file could not be found"error.
updating InterfaceB to correctly return IEnumerable as its implementor ClassB did solved the problem, unfortunately the error message was vague and also the fact that the compilation worked makes me suppose that maybe there is something to fix in the compiler
A coworker was running into this problem and the cause was eluding us. Eventually we realized that the project directory (and therefore the path to the NuGet packages) contained %20 (thanks, some Git gui tool which shall not be named) and the error messages showed that the compiler was looking for an very similar-looking path but one which had to %20, rather a space. Apparently something in the build system somewhere performs HTML-decoding on local filesystem paths.
Renamed the working copy directory and everything started working.
I had this issue too.
It started after I did a little folder tidying in my project.
I then tried to compile and got many duplicate class errors. (despite them not being duplicated. I think the linking was just out of wack)
Upon checking these, the errors would all disappear leaving only the "Metadata file ...debug\application.exe could not be found" error.
I solved this by looking in the build output window to find which classes were duplicated.
I would then right click the class name and "go to definition".
there will be two definitions to select from, open them both, the second definition will seem to open the same file again, however the second one will identify as the error source(red underline).
Delete all the code out of the file and save(This will not effect your actual file).
This should now compile correctly.
Ensure that there are no spaces in the path to your project...
I am using Windows 10 with Visual Studio Community 2019 and I was cloning a multi project solution as it was from a GIT repo. I was having this error with all other dependencies in the solution along with a E_POINTER error. Its path, inherited from GIT, had spaces like C:/repos/MY PROJECT NAME/ ...
I deleted it, cloned it again and make sure that its path contained no spaces like C:/repos/MY_PROJECT_NAME/ ...
That fixed my problem.
I had same issue too.
In my case, I recently add an internal class to somewhere in project. One of the dependencies in solution has same class name and both of them are added correctly to references.
I changed my last activity and rebuild, it works.
Be sure that your compiler messages are valid. In my case I catch reference error from there, not listed as an error in Error List.