Here's my problem:
I am using a DLL library (not from the .NET framework) which contains a System namespace with the Tuple and Lazy classes.
When I try to compile my project the compiler throws some errors stating that these classes exist in mscorlib.dll and another DLL.
So, how can I use the classes from the .NET Framework and don't delete the reference to the other DLL?
If they have the same namespace etc, then the only way to disambiguate is to use an extern alias. In the solution explorer, change the Aliases property of this rogue reference to something else, for example foo (instead of global).
Now, in the class files where you need types from that assembly, you'll have to add (at the very top):
extern alias foo;
And then later down in the code you can use:
foo::Some.Namespace.TheType
or equally:
foo.Some.Namespace.TheType
Basically, the alias name becomes an extra level of disambiguation. The default alias, for reference, is global. Note also, however, that while the compiler is fine with this, the VS2012 IDE still has a few... kinks with extern alias: https://connect.microsoft.com/VisualStudio/feedback/details/770464/ide-but-not-compiler-incorrectly-reports-an-error-when-using-extern-alias-to-disambiguate-types
It sounds like the third party library you're using was designed to be used for .NET 2.0 or .NET 3.5.
I'd be very surprised if the third party didn't also supply DLLs for .NET 4+ - I strongly suspect you can just replace the DLLs which the ones for your target framework version and rebuild.
This is probably a library targeted for .NET 2 or 3.5, which added own implementations for .NET 4 features (Tuple and Lazy). Look for an updated .NET 4 version of this library.
Related
I'm trying to programmatically create satellite assemblies for .NET5 and .NET6 apps using code I've written which targets .NET7. The code extracts the various resource properties, like form/button text, sizes and positions, using ResourceReader and stores names, values and types of each property, so that later on, we can recreate this information in the satellite assemblies using ResourceWriter. Some of these types are simple like System.Int32, System.String, and others are a bit more complex such as System.Drawing.Size.
There are issues with this approach because types extracted from a given localisable assembly are instantiated using the currently executing runtime i.e. if my code targets .NET 6 and the assembly targets .NET5, calling GetType on each resource from the dictionary returned by ResourceReader creates .NET 6 types, not 5. So, in effect, each type's target assembly version is being bumped up just by virtue of being instantiated.
If my code and a localisable assembly target the same runtime, it works fine, but if my target runtime is newer than the assembly's, the assembly will crash on startup because it's trying to load "foreign" types that belong to a different set of .NET reference assemblies.
I've spent absolutely ages trying to figure this one out, and the suggestions I've read include creating the satellite assembly using .NET Framework instead, but it doesn't solve my problem as I still need to "downgrade" my types to the same version as what was in the main assembly.
I've also overriden the ResourceWriter.TypeNameConverter delegate to change the assembly version properties in each type, but that didn't work either.
I have a project that uses System.Runtime.Serialization assembly. I am using the type DataContractSerializer from that assembly, but I have a problem.
There are two assemblies:
C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework.NETFramework\v4.0\System.Runtime.Serialization.dll
C:\Windows\Microsoft.net\Framework\v4.0.30319\System.Runtime.Serialization.dll
Both of them have the same version - v4.0.30319. The first one have 429kb size, and the second one 1037kb. I used reflector to see the list of classes, and the first one doesn't have the class that I need (DataContractSerializerSettings). However, the second one does have it.
Why are there some big difference in size and classes for that assembly? Will it be ok, if I use the second one, instead of the first?
.NET version 4.0 made a big change in the way framework reference assemblies are done. Previously, the reference assembly was a simple copy of the runtime assembly, the one stored in the GAC. That however caused some painful problems. Notable is the WaitHandle.WaitOne(int) overload, it was added in the .NET 2.0 Service Pack 2 update (aka .NET 3.5). Programmers used it without noticing that it was an added method, the mscorlib assembly version number was still 2.0.0.0. But then discovered their program failed when running on an unpatched version of .NET 2.0. Very nasty kaboom, MissingMethodException without a hint why such a common method could be missing.
To prevent this kind of breakage, the .NET 4.0 reference assemblies are kept separate, in the "%programfiles%\Reference Assemblies" directory as you found out. And they are special assemblies, they only contain the metadata with all the IL stripped out. Which is why the assembly is so much smaller.
Microsoft now can improve the .NET 4 code and add public classes and methods without causing this kind of breakage. And have done so profusely, updates 4.01, 4.02 and 4.03 have shipped since the original 4.0 release.
The reason you are having trouble with the DataContractSerializerSetting class is thus easily explained, it just doesn't appear in the reference assembly. It got added, probably in one of those incremental updates. And you should not try, your program will break on a machine that doesn't have the update. You should wait until .NET 4.5, the version that added it to the reference assembly. You can invoke DLL Hell if you really want to.
I work on a project target WP 7.5 and above, I add a packages using the Nuget in VS 2012 which name is Coding4fun(Controls).
After that, the IDE give me a warning,
Warning 1 The predefined type 'System.Tuple' is defined in multiple
assemblies in the global alias; using definition from
'c:\Users\Gao\Documents\Visual Studio
2012\Projects\TFSGit\xicihutong\packages\Coding4Fun.Toolkit.Controls.2.0.5\lib\wp71\Coding4Fun.Toolkit.Controls.dll' C:\Users\Gao\Documents\Visual
Studio 2012\Projects\TFSGit\xicihutong\xicihutong\CSC xicihutong
The app runs OK, but how to solve this warning?
From Compiler Warning (level 1) CS1685
This error occurs when a predefined system type such as System.Tuple
is found in two assemblies. One way this can happen is if you are
referencing mscorlib from two different places, such as trying to run
the.Net Framework versions 1.0 and 1.1 side-by-side.
The compiler will use the definition from only one of the assemblies.
This problem occurs probably System.Tuple is defined in two different assemblies. Probably your Coding4Fun.Toolkit.Controls.dll has too besides mscorlib.dll.
If you want to look them both you can check them;
Get a decompiler like ILSpy or Jetbrains dotPeek.
Add all 3rd party assemblies.
Search for System.Tuple
But how to solve this warning?
You can define your 3rd party assemblies reference some aliases. You can follow in your project
Reference -> Properties -> Aliases ->
And change "global" to something different.
Check out for information extern alias (C# Reference)
Newer version of c4f toolkit has resolved this issue.
I have an error, when I try to build my .net 4, c# project. Everything works great, but when I add an external reference to a given DLL, it stops working, it can't build, throws this type of some errors:
Error 36 The type 'System.Tuple' exists in both 'C:\Program Files\Reference Assemblies\Microsoft\Framework.NETFramework\v4.0\mscorlib.dll' and 'C:\Projects\Project1\ExternalRefernces\SharpSNMP\SharpSnmpLib.dll' C:\Projects\Project1\CheckerStore.cs 17 21
Note, I did not do anything with the new library, just added as a reference. Any ideas?
You can solve this problem by specifying an external alias. Select the SharpSNMP reference in your project. In the properties window change Aliases from global to say SharpSNMP. In your code type this
extern alias SharpSNMP;
...
System.Tuple<T1,T2> sysTulpe;
SharpSNMP::System.Tuple<T1,T2> sharpTulpe;
or
extern alias SharpSNMP;
using SharpSystem = SharpSNMP::System;
...
System.Tuple<T1,T2> sysTulpe;
SharpSystem.Tuple<T1,T2> sharpTulpe;
See Aliases: overcoming name conflicts part 2: extern alias
What you can do is either change the target version to 3.5 or make some changes in the SharpSNMPLib. The source can be fetched from here or here.
The changes you need to make is specifically moving the System.Tuple type somewhere else.
Edit:
I belive you have added a reference to a precomplied DLL. A DLL that is NOT compiled for framework version 4. What you need to do is download the source code (see links above) and compile the project with target version 4.
Why you need to do this is because there are conditional build parameters depending on the framework target version. The SharpSNMPLib System.Tuple is used for version <= 3.5 and the framework System.Tuple is used for version >= 4.
Edit:
Reproduced your problem using framework System.Tuple and SharpSNMPLib.dll.
Successfully built SharpSNMPLib targeted on version 4.
Successfully built application using framework System.Tuple and the new SharpSNMPLib.dll.
Simply go to your CheckerStore.cs file, line 1721 (if I'm right). Find the Tuple class, and reference it using it's fully qualified name.
The library for some reason re-implements some system types. Likely reason is to make code to be source level compatible when using older versions of the framework.
Most likely there is a version of this SharpSNMP library that works with 4.0 framework. Check if you already have correct on in your source tree. Check with creators of the library what versions of the assembly you need to use with given framework version and what is recommended way of doing it.
I added a DLL to my project. The DLL contains the namespace test.security. Now, test.security is not recognized. Why is this?
I am using this DLL in other projects and I have no other problems.
Are you using Client Profile as a project target? Consider this scenario:
Project A -> Project targets .NET Framework 4.0
Project B -> Project targets .NET Framework 4.0 Client Profile
Project A is referenced by Project B. Namespaces in Project A are not recognised in Project B.
If ths scenario matches, this is due to a target mismatch. Client Profile supports a subset of the BCL of the full framework. If an assembly is dependent on using the full framework (like requiring types from System.Web, etc.) then it won't be useable from an assenbly that only supports Client Profile.
Easy solution, change Project B to .NET Framework 4.0 (not Client Profile).
It often depends on what is in that namespace; for example, if nothing is in there then the namespace doesn't really exist.
It is also possible that you are missing some other dependency which means that the compiler can't use (until the reference is added) any of the types in that namespace (for example, if the types in that namespace all depend on some type from Another.dll, and you haven't referenced Another.dll).
It is possible you have referenced the wrong version of the dll, and the version you are referencing doesn't have that namespace.
It is possible the compiler is already telling you about a reference problem, meaning it can't use it - look in the errors/warnings list. For example, it could be a physically missing file, or a .NET version mismatch, or a strong-naming issue, that means it can't use the reference.
1.remove the reference and add it again
2.Close the solution and re-open it
3.Create a new solution and add all old ones in it
Way late to the party, but obviously this came up in a recent search, so this is to help the newbie who lands here. Here's one more thing to verify.
As quoted from Dummy01's comment to his answer to this question:
Pack C# project to dll or another library
"DLL is in your project's bin or release folder. If it looks empty is because your classes are defined as private or internal. You should change the names you need to see outside your dll to public."
Check your DLL,s .NET version and your host project's . NET version. Most probabbly there are different and somehow it creates problems in your specific case.
Regards.
I also faced this problem. In my case I tried removing the reference, rebuilding the referenced project, and then adding it again, but the problem still persisted.
The problem in my case was the classes in the targeted project's namespace were not public. This meant there was nothing accessible in that namespace, so it didn't really exist.
Setting them to a public access level solved the problem. Hope it helps someone! :)
I had the same problem. I changed a console application to a class library in the project properties. That fixed it.
I would like to add a cause for this, found in VB.NET (Visual Studio 2010, in my case; yours may vary).
As an example, I have two projects: P1 and P2.
P1 is an Application, and P2 is a Class Library.
Stipulations:
There is a reference in P1 to P2
Both P1 and P2 are targeting .NET 4.0 (full, not Client)
Both P1 and P2 target x86 (not that it likely matters)
There are 0 errors and 0 warnings
However, in P1, it is not possible to declare an 'Imports P2...' expression, nor to use any Shared methods found in P2. It exactly as if the Namespace P2 does not exist, though the reference is there.
Cause: P2 was converted to a separate assembly from code in which all methods were contained in a VB.NET Public Module. However, the 'Module' was not re-typed as a Public Class.
No errors whatsoever, but the P2 Namespace was entirely unavailable to P1 until a Public Class was created.
Of note, it was not actually necessary to convert the original Module to a Class. It was only necessary to declare some Public Class (even if it is empty) within the P2 Namespace, and then all methods found in that Public Module were available.