DLL compiled with .NET 4.5 doesn't work

Hi!

I'm trying to use Microsoft.Kinect.Tools.dll, a Kinect Native DLL compiled with .NET 4.5 which I imported into my Unity project to record videos in .xef and .xrf format.

Despite all my attempts, Unity never detects this DLL as part of the project, and always gets this error:

Code (CSharp):

1. Assets/KSRecordTest.cs(4,24): error CS0234: The type or namespace name `Tools' does not exist in the namespace `Microsoft.Kinect'. Are you missing an assembly reference?

I even tried to add the reference to the .csproj file by hand:

Code (CSharp):

1.     <Reference Include="Microsoft.Kinect.Tools.dll.dll">
2.       <HintPath>Assets\Plugins\Microsoft.Kinect.Tools.dll</HintPath>
3.     </Reference>

But I've only been able to make Visual Studio import it properly until Unity rewrites the .csproj files again (I could write "using Microsoft.Kinect.Tools" and use it for a while in my script).

Does this happens because .NET 4.6 is still on experimental phase, therefore being impossible to use higher .DLLs than .NET 3.5?
Or maybe it has to do with the DLL being Native. I'm not really sure.

Any help is appreciated.

Thanks!

 

I was actually trying with the experimental runtime (.NET 4.6). Sorry I didn't clarify it before.

Yes, it gets included in the build. Anyway, the DLL doesn't work in the build nor the editor.


I made a clean new project with Kinect Tools DLL only. This is my config:



This is how a script looks in Visual Studio (Microsoft.Kinect.Tools never appears in the References list):



And this is how it looks with the DLL added by hand to the .csproj file (Anyway, like you said, Unity ignore this):



Here is the DLL I'm using:
https://drive.google.com/file/d/0B2P1mRmx83AwOHZlOGc2THNVOVE/view?usp=sharing


Is there some special way to get a DLL compiled against .NET higher than 3.5 work with the .NET 4.6 experimental runtime?
If not, will the .NET 4.6 final runtime fix this issue?

Thanks for answering!

 

I did that and now I'm getting this error:

Code (CSharp):

1. error CS0006: Metadata file `Microsoft.Kinect.Tools.dll' could not be found
2.  
3. Compilation failed: 1 error(s), 0 warnings

I tried using -r:Microsoft.Kinect.Tools (without .dll extension) and placing the DLL inside Plugins folder, but it doesn't seem to fix the problem. Also, the Microsoft.Kinect.Tools.dll meta file exists, so I don't know why it doesn't work.

Do you have any solution for this?

Thanks!

 

It worked with: -r:Assets/Plugins/Microsoft.Kinect.Tools.dll

Anyway, a new error appeared:

Code (CSharp):

1. FileNotFoundException: Could not load file or assembly 'Microsoft.Kinect.Tools, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies.

This one is strange, because my script still has errors:


And the Microsoft.Kinect.Tools reference wasn't even imported:


But Unity doesn't show anything wrong on console:


This is only until I press the Play button, and then the error I showed above pops up:



This only happens inside Unity, because I tested the same code in an external VS Project with almost no references and it worked (could record videos and all):




What could it be?

 

I also tried that but didn't not work.

Here is the Unity project, in case you want to try it by yourself: https://drive.google.com/open?id=0B2P1mRmx83AweGQ3UlRwcXB6OWs

if I get it to work I'll reply again explaining how I did it

Thanks for answering!

 

I decompiled the dll with dotPeek (JetBrains), and looking at some classes I saw this "using <CppImplementationDetails>":

So I guess Microsoft.Kinect.Tools.dll was written in C++/CLI.

Is this the only way to use a Native DLL in Unity?:

Code (CSharp):

1. [RootSystem.Runtime.InteropServices.DllImport("NativeDLLName"]

If that's the case it doesn't help me.

Do you know another possible solution? If not, will be possible in future versions of Unity to use Native DLLs in the same way as Managed DLLs?

 

Oh, I'll see how I manage then.

Thanks for all the help Josh!

 

Well, after some attempts I made it work with [DllImport]. I'll leave the link to the project for anyone interested in using it and learn from it: https://mega.nz/#!pkpU2YDZ!Vo5keYsxxpvav90OE6CQK4K63uryq8h-r4vyWWCbcoI.
It includes the Unity project (C#) and the C++ project (which builds a DLL whose purpose is to set up connection methods between the Unity project and Microsoft.Kinect.Tools.dll).

Some things to keep in mind:

• The Scripting Runtime Version has to be .NET 4.6 (Edit > Project Settings > Player).
• Both DLLs, Microsoft.Kinect.Tools and KinectUtilities (the one I made), have to be inside the Unity Editor folder (along with the .exe) in order to get loaded. The same with the Build, they have to be placed inside the build folder, next to the .exe.
• In C#, when using [DllImport] to call a native method, every parameter that use pointers (*) in the C++ code require this attribute [MarshalAs(UnmanagedType.LPStr)] before the type.
• When programming a Native DLL in C++ (not necessarily this case):
  • In headers, extern "C" __declspec(dllexport) has to be included before every method that will be called with [DllImport] in C#.
  • In the project properties, Common Language Runtime Support needs to be enabled.
  • Also, if another DLL is being used (added to References), it's .NET version has to be equal or lower than the project's one. This can be changed in the project .vcxproj file, adding <TargetFrameworkVersion>v4.5.2</TargetFrameworkVersion> (or any other version) in the label ProjectConfigurations. The Solution Platform must be the same than the external DLL too (I used x64 for Microsoft.Kinect.Tools).

I hope this can be helpful to someone in a future!

 

Oh, you are right, it should only be used to marshal strings.

Thanks for the correction!

 

Hi! Thank you to sharing your project!
I've tried it but failed ><
First question: you wrote that dlls have to be inside the Unity Editor folder. What folder exactly did you mean? Assets/Editor? Assets/Plugins/Editor? Another one?
Second: after some googling I've found out, that, maybe, there is a mistake in code and i need to use
[DllImport("KinectUtilities", ...
without ".dll" but not
[DllImport("KinectUtilities.dll", ...
But after that I've got a crash of whole unity editor, not only an error to the log.

 

Sorry for the late response GeorodruS!

I was referring to this when I said DLLs shall be inside the Unity and the builded game (.exe) folder:



As for the .dll extension, I just tried executing the code only with [DllImport("KinectUtilities") and it worked just like when the extension was included.

If you still have problems, this time I will be more alert to the replies!

 

hello i was facing a problem related to this all my visual studio projects are in .net framework 4.6 and in my unity scripting runtime version is set to .NET 4.x equivalent and api compatiblity is set to .NET .4.x while i am importing my visual studio project dlls to unity assets i am getting an error stating :
Assembly 'Assets/Connection.dll' will not be loaded due to errors:
Unable to resolve reference 'PresentationFramework'. Is the assembly missing or incompatible with the current platform?
Reference validation can be disabled in the Plugin Inspector.


i dont know what did i miss
i did the same procedure in unity 2017.2.5 i worked i set both the frameworks to 4.6 and added my dll files in assets folder but i was unable to build in unity so i upgraded to unity 2019 version now i am struct in this my present unity version in 2019.1.7

any help would be appreciated
thank you