Using dll's from C#?

Questions & Answers
1

Hello

I am trying to use a dll I made in C# .net 2.0 without any luck. From what I have read, the dll should be placed in the asset folder and can then be used as any other scripts.

My Dll:

using UnityEngine;
using System;
using System.Collections.Generic;
using System.Text;

public class SerialGPS_DLL2 : MonoBehaviour
{
    public void SerialGPSInit(string comPort, int baudRate)
    {
        //Some code
    }

    public void SerialGPSClose()
    {
        //Some code
    }

    public void SerialGPSUpdate(ref double latitude, ref double longitude, ref string status)
    {
        //Some Code
    }
}

How I use it:
Adding dll as referance in Visual Studio(just to get intellisense).

using UnityEngine;
using System.Collections;
using System.Runtime.InteropServices;

public class SerialGPS : MonoBehaviour 
{
    private SerialGPS_DLL2 m_cSerialGPS_DLL;
    
    void Start () 
    {
        m_cSerialGPS_DLL.SerialGPSInit("COM3", 4800);
    }

    void Update()
    {

    }
}

The error i get:

Internal compiler error. See the console log for more information. output was:
Unhandled Exception: Mono.CSharp.InternalErrorException: Assets/SerialGPS.cs(5,14): SerialGPS ---> Mono.CSharp.InternalErrorException: Assets/SerialGPS.cs(12,28): SerialGPS.m_cSerialGPS_DLL ---> System.TypeLoadException: Could not load type 'SerialGPS_DLL2' from assembly 'SerialGPS_DLL2, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null'.
  at (wrapper managed-to-native) System.Reflection.Assembly:InternalGetType (System.Reflection.Module,string,bool,bool)
  at System.Reflection.Assembly.GetType (System.String name, Boolean throwOnError, Boolean ignoreCase) [0x00000] in <filename unknown>:0 
  at System.Reflection.Assembly.GetType (System.String name) [0x00000] in <filename unknown>:0 
  at Mono.CSharp.SimpleName.Error_TypeOrNamespaceNotFound (IMemberContext ec) [0x00000] in <filename unknown>:0 
  at Mono.CSharp.SimpleName.ResolveAsTypeStep (IMemberContext ec, Boolean silent) [0x00000] in <filename unknown>:0 
  at Mono.CSharp.Expression.ResolveAsBaseTerminal (IMemberContext ec, Boolean silent) [0x00000] in <filename unknown>:0 
  at Mono.CSharp.Expression.ResolveAsTypeTerminal (IMemberContext ec, Boolean silent) [0x00000] in <filename unknown>:0 
  at Mono.CSharp.MemberBase.ResolveMemberType () [0x00000] in <filename unknown>:0 
  at Mono.CSharp.MemberBase.Define () [0x00000] in <filename unknown>:0 
  at Mono.CSharp.Field.Define () [0x00000] in <filename unknown>:0 
  at Mono.CSharp.TypeContainer+MemberCoreArrayList.DefineContainerMembers () [0x00000] in <filename unknown>:0 
  --- End of inner exception stack trace ---
  at Mono.CSharp.TypeContainer+MemberCoreArrayList.DefineContainerMembers () [0x00000] in <filename unknown>:0 
  at Mono.CSharp.TypeContainer.DefineContainerMembers (Mono.CSharp.MemberCoreArrayList mcal) [0x00000] in <filename unknown>:0 
  at Mono.CSharp.Class.DefineContainerMembers (Mono.CSharp.MemberCoreArrayList list) [0x00000] in <filename unknown>:0 
  at Mono.CSharp.TypeContainer.DoDefineMembers () [0x00000] in <filename unknown>:0 
  at Mono.CSharp.Class.DoDefineMembers () [0x00000] in <filename unknown>:0 
  at Mono.CSharp.TypeContainer.Define () [0x00000] in <filename unknown>:0 
  at Mono.CSharp.ClassOrStruct.Define () [0x00000] in <filename unknown>:0 
  at Mono.CSharp.Class.Define () [0x00000] in <filename unknown>:0 
  at Mono.CSharp.RootContext.PopulateTypes () [0x00000] in <filename unknown>:0 
  --- End of inner exception stack trace ---
  at Mono.CSharp.RootContext.PopulateTypes () [0x00000] in <filename unknown>:0 
  at Mono.CSharp.Driver.Compile () [0x00000] in <filename unknown>:0 
  at Mono.CSharp.Driver.Main (System.String[] args) [0x00000] in <filename unknown>:0

My only theory at the moment is that I am building my dll in a way that is not supported.

2

You can drop .Net DLLs in your project, compiling order has no effect here as all Unity scripts are also compiled into .Net DLLs before the scene is run.

However, I think your issue comes from creating an instance of MonoBehaviour that way. Remove the MonoBehaviour subclass part from the SerialGPS_DLL2 class definition and try it.

3

I striped the dll for all functionality and found out it didn’t like the System.IO.Ports namespace I was using.

After testing System.IO.Ports in a new class in Unity i got the error: “the type or namespace ‘port’ does not exist in namespace ‘System.IO’”.

So my problem does not seem to be dll related after all. Found a post about System.IO.Ports here.

4

in the player settings change the .NET 2.0 subset to .NET2.0 it will work…

5

Yeah… lame… really… really… LAME error message. Just cost me several hours while I’m on a deadline. My .Net common libraries reference SYstem.IO.Ports… I need them to debug a serial peripheral device.