Generate Dll For Unity In Mono

1 . Create an empty C# class library

2. Compile you class

Change you target .Net Framework (int unity 5.5.1, it need to be .NET3.5 or lower

then build your project

get back to you project in files, you will get you own dll under path bin/Debug

drop to you unity project

Use dll in unity

Add references of UnityEngine.dlland/orUnityEditor.dllto the project, you can do so by browsing into the folder (typically, depending on your specific Unity3D installation directory):

Mac:              /Applications/Unity/Unity.app/Contents/Frameworks/Managed/

Windows:      C:\Program Files\Unity\Editor\Data\Managed