System.IO.File for .NET Standard My Class Library for .NET Standard My Application User Interface for .NET Standard Build時 Android実行時 iOS実行時 System.IO.File for Mono.Android My Class Library for .NET Standard My Application User Interface for .NET Standard Mono.Android Runtime java.io.File My Class Library for .NET Standard My Application User Interface for .NET Standard System.IO.File for Mono.iOS Mono.iOS Runtime NSFileManager ? and Switch Bait
Framework Side .NET Framework Runtime Win32 API System.IO.File for .NET Framework My Class Library for .NET Framework My Application for .NET Framework Original .NET Core Windows Runtime Win32 API System.IO.File for .NET Core My Class Library for .NET Framework My Application for .NET Core .NET Coreで実行時 .NET CoreでBuild時 System.IO.File for .NET Framework My Class Library for .NET Framework My Application for .NET Core and Switch Bait
Side Framework Side .NET Framework Runtime Win32 API System.IO.File for .NET Framework P/Invoke My Class Library for .NET Framework My Application for .NET Framework .NET Core Runtime Win32 API System.IO.File for .NET Core P/Invoke My Class Library for .NET Framework My Application for .NET Core
Side Framework Side .NET Framework Runtime Win32 API System.IO.File for .NET Framework P/Invoke My Class Library for .NET Framework My Application for .NET Framework .NET Core Runtime Win32 API System.IO.File for .NET Core P/Invoke My Class Library for .NET Framework My Application for .NET Core この二つは完全に別物です My Class Libraryから利用している クラス・メソッドがCoreに存在しない 場合、実行時エラーとなります