Project reference not working in VisualStudio2010 - c#

I've got a Solution with lots of projects and all but one of them is behaving. The one that is not working is a ConsoleApplication, and it relies on C# Class Library project. I've added a reference to the library project, and add the namespace (which I've checked is correct), but everywhere I reference the classes in my library, I get:
The type or namespace 'MyClass' could not be found (are you missing a using directive or an assembly reference?).
The library project is building successfully (I can see the DLLs appear in the bin folder) and I've tried a project reference, and also a reference to the DLL itself. Neither works.
Also, all projects are set to build with a platform target of 'Any CPU'.
I've tried pretty much every suggestion I've come across on forums with no success. Can anyone shed some light on what's going wrong?
Thanks
This solved the problem:
The console application had a Target framework of .NET Framework 4 Client Profile, whereas the library just had .NET Framework 4. I set the console app to .NET Framework 4 and it all builds perfectly.

My bet is on a framework mismatch between your library and you app...
Check if your library is not building with a superior version than you app, or if your app is building with a Client profile flavor

It is probably that one of your DLLs references some part of the .net framework that is not referenced in your console application. For example if one of your class library projects has asp.net server controls in and references System.Web, but your console application does not reference System.Web it will not build and you will get that error. But it is not obvious because the DLLs referenced are stored in the GAC so they would never appear in your bin folder.

I had to simply restart visual studio for reference to work but make sure you have reference added in .csproj file.
If you still experience the issue, make sure the class you're referencing is public and that Asp.net core Framework version match.

Sounds weird,
Have you tried to remove the reference of the project and add it again? Check if your console app has got all the right references.
You could also inspect the .csproj file and see if everything is correct in there.

Just Check that you "Class Library" project has classes in it or if it is a data access layer project which include only a .edmx Model check the Model designer is found and it generates fine.
Good Luck

I worked with syncing the framework, but still, it was giving issue.
So I tried another way.
Right-click on the dependency, and select Add project reference. I added the required project then the error was gone.

Related

Missing System DLL's in .NET project

I have a .NET solution consisting of several projects - most of these are just simple c# libraries. One of them is an MVC web application.
All the references of every project is missing references. Here is an example:
I have de-selected all projects for build except this one (shown above) simple c# library project which has no dependencies on any other in the solution.
I've checked things like the .proj file in Notepad but can't see anything unusal.
If I remove one of the references such as System.XML and then re-add it, it gets re-added but still with the missing warning icon! So the Dll's are in the .NET frameowrk directory as you'd expect.
I'm really quite stumped with this.
It's .NET framework 4.5, Windows 7, x64.
Thanks in advance for any thoughts / help!
Kind Regards
Richard
Several points to check to know why they seem to be missing:
Paths
Assemblies: Are they built for the same .NET version of your
project (Portable, not portable, windows phone, etc...)
For the query you asked, you can refer the below link
How to add references and nugets in visual studio project template?
For the references, according to the image, it may refer to the GAC and not the local bin folder of the solution.
Remember, the best way is always to maintain the references in the Bin/Reference folder and then refer from it. Add them to the solution so that you may not loose them when you compress and move them to another system.
The following link will help you how to add the references
https://msdn.microsoft.com/en-us/library/7314433t(v=vs.90).aspx
Following below steps resolved the issue.
Ensure the .dll exists in the properties path
Still,if issue exist,then click on properties that fix the problem

Namespace not recognized with Any Cpu

I recently had an issue with VS2010, C#, and .Net 4 where I could not use the namespace from my referenced assembly (call it AssemblyA). It is similar to the issue here.
I was able to correct the problem by setting AssemblyA to target x86 platform instead of Any Cpu.
My question is why did changing the platform target to x86 allow me to use the namespace from AssemblyA in my project?
I want to note that I was able to reference AssemblyA in other projects without changing the platform target. Also all of my references were project references.
EDIT: Apparently I am mistaken. It is not working even when changing to x86. Any ideas what could be causing this?
Update: All my projects are using the full .NET 4 profile.
EDIT:
After doing some testing I have some more information. When I switch between Debug/Release builds (Doesnt matter the order I switch) and do a clean on AssemblyA then I am able to use the namespace no problem. As soon as I rebuild AssemblyA then I can no longer use the namespace. It doesn't seem to matter what platform I am targeting.
You need to make sure that the project in which you are referencing the assembly is set to ".NET 4 Full Profile" instead of the default "Client Profile". If your DLL is using classes from the full profile and your assembly is set to client profile, it can't reference the DLL.
So just right click on your project, then click Properties. Then under the Application tab, look at the Target Framework. Make sure it isn't set to .NET Framework 4 Client Profile
I am not sure what the deal is here but to workaround I just created a completely new project and copied the code. The new project is setup identical to the project that was giving me issues. However I can reference the new project in my other project with no problems.

C# dll not found at compile time

I'm writing an application in .Net 3.5.
I have 3 projects in the solution so far. When adding the references to the other projects from my main project, the intellisense manages to find the classes from the other project's dlls but at compile time it seems to be "loosing" the reference.
This might be because I initially created the project with target framework .Net 4.0. However since I needed to use the ASP.NET web services I had to downgrade to 3.5.
Any help will be greatly appreciated.
The referrenced projects must be Copy Local : True
Referrence -> Properites ->Copy Local : True
Batch clean all projects in your solution, make sure all the projects in your dependency graph target the .NET 3.5 framework. Check the reference's HintPath in your .csproj file (open with text editor) for references to external DLLs and make sure they're all <=3.5.
However since I needed to use the ASP.NET web services I had to downgrade to 3.5.
There are also several different web service projects in .NET 4. I don't quite understand this move.
You have project references, intellisense sees your referenced classes but when compiling, the compiler seems not to find the referenced assemblies.
I see two possible reasons for this behaviour:
Your main project references a lower version of the .NET framework than your library projects (this is the most likely cause).
Your library projects won't get built at all / or in the wrong order (check the settings in the configuration manager. Open it with a right click on your solution in the solition explorer).

C# Windows Service can't find namespace of dll, works in other projects

This is a weird one.
I created a new Windows Service in C#, and want to re-use some of the code we created before that's in a Class Library.
The project is loaded in the solution along with the service. Both target .NET Framework 4.0 (not client profile).
I tried adding a project reference, and it worked for a short while. After working on some old code that I was rewriting, when the project compiled again, it complained that it no longer recognised the namespace for the using statement.
I've made sure to clean the solution & rebuild, but no dice. Sometimes VS can have a bad day, so I restarted VS, but this also didn't work.
I then build the DLL, and add a reference to it via 'browse', also no dice. Then I tested it on another project, but after adding it, it works instantly, so it's not the DLL.
I then checked with other libraries in the solution, but I was able to add a reference to them in the service and access their namespace without a problem.
I'm out of ideas here, anyone got an idea of what to do here?
Thanks,
Nick.
Almoast forgot: the weird thing is, that if I open up the Class view, and expand the 'References' section, the namespace/dll doesn't show up there either... it's a real conundrom...
I should pay more attention to warnings:
C:\Windows\Microsoft.NET\Framework\v4.0.30319\Microsoft.Common.targets(1360,9): warning MSB3253: The referenced assembly "" could not be resolved because it has a dependency on "System.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" which is not in the currently targeted framework ".NETFramework,Version=v4.0,Profile=Client". Please remove references to assemblies not in the targeted framework or consider retargeting your project.
So, I'm a ready idiot for checking the DLL's target framework but not the Windows Service :)
The problem is my DLL uses System.Web, which is not part of the .NET 4 Client Profile framework target. Changing the Service's Target Framework to 4.0 fixed it.
If the class view doesnt show the types that should be there, the actual dll you're compliling against is not the correct version.
There could be several reasons for this
A previous compilation of the dll might still be around
The project might reference another, older, binary version of the library rather than having a project reference
Another project mgiht be referencing an old version of the dll, and have copy local set to true. When that project is compiled it overwrites the new version of the library
Make sure all projects in the solution use project references, and remove all binaries you can find.

Namespace cannot be found after changing target framework from v4.0 to v3.5

I have 2 projects in a solution, 1 a dll, the other an exe. Both were using .net version 4.0 however no 4.0 specific libraries were used so it should be possible for me to safely change them to 3.5
I did this under both project properties, I built the dll fine. Now when i try to build the exe it cannot find the dll's namespace. I have readded the reference, but it still cant see it. When I reverted the .net version it did say I might have to modify the project files before it builds. I have tried to search for a solution via google but the key words I am using are too commonly used. Can anyone advise?
Many thanks, Chris
Edit:
Tried the following already..
Reference DLL specifically whilst ensuring not 4.0 copy
Delete bin and obj folders
Restart VS
Rather than referencing the output DLL, have you tried setting it as a project reference instead.
Also, have you done a clean build of the solution incase any .Net 4.0 files were lingering? You can manually clean the project by deleting the bin and obj folders.
Have you tried removing the projects from the solution, creating a new .net 3.5 project and compiling that. Then add in the ddl project (Add -> existing project) and compile, then add in exe project without reference, compile then add in the references.
Odd question, but have you check the name spaces still. Can you call in your project the namesapce, i.e. using mydllproject.model.myengine
I would open your project files as XML. To do this, close the soltion and reopen the projects only by clicking the down arrow on the File/Open button and selecting Open With... XML (Text) Editor. Check to make sure each project has a ToolsVersion="4.0" in the header. Check the RootNamespace and TargetFrameworksVersion elements to see if they have the values that you expect. At the bottom of the file, check the ProjectReference element within the ItemGroup. Make sure the GUID in the project reference matches the GUID that is defined in your solution file.
Finally, make sure you clean your project before you rebuild it. If you're using source control, check out the project into a new, empty sandbox.
Good Luck!
-Put dll and exe in 3.5
-Compile the dll only
-Delete the reference to the dll and readd it
-Rebuild the solution
Check the DLLs that you are referencing what kind of target runtime they require, especially the "Engine.dll". You could do this with the .NET Refractor for example. If they are compiled for v4.0, then yuou need to get versions for an earlier version of .NET runtime.
I had a very similar problem to this. In my case it I had two projects, a 'class library' and a windows forms application in the same solution.
After changing the target framework of both the projects to .NET4.0 framework, and adding a reference to the class library in my windows forms application, it wouldn't detect the namespace of my class library.
Here is what I did that finally solved the problem:
Created a new project with .NET 4.0 framework as the target framework. I imported all my forms and classes into this project from the original solution.
Added the existing class library as a new project.
Added a reference to the class library project from my windows forms project
For each of the class files under the class library project, I set the 'Build Action' to 'Compile'
Right-clicked the class library project and selected to 'Rebuild'.
Then when I go into my windows forms projects, I can see the namespace when I use the
'using namespace_name' statement.
Note: Maybe you do not need to create a new project like I did in the first few steps. But changing the Build Action definitely did the trick.
Hope it helps.

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