2. Building great libraries using .NET Standard
Aaron Amm Theeranit
Senior Software Engineer

3. Covers: Not Covers: What is .NET Standard
How to create .NET Standard class library project
Consume your .NET Standard in your .NET Framework project and .NET Standard project
.NET Standard work under the hood
Type forwarding and netstandard.dll
Not Covers:
Multiple target .NET Standard class library and platform specific
Consume .NET Framework class library and .NET .Core library in your .NET standard library
Package Nuget Package

4. What is .NET Standard?

5. What is .NET Standard? .NET Standard is a specification
4/3/2019 5:57 PM
What is .NET Standard?
.NET Standard is a specification
A set of APIs all .NET platforms have to implement
.NET Standard
.NET Core
.NET Framework
Xamarin ~
HTML specification (W3C)
Browsers (Chrome, Edge)
© 2014 Microsoft Corporation. All rights reserved. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

6. .NET Standard in context
.NET FRAMEWORK
.NET CORE
XAMARIN
.NET Standard

7. All the foundational APIs
What’s in .NET Standard?
Microsoft.Win32.SafeHandles
System.IO.MemoryMappedFiles
System.Runtime.Serialization.Formatters.Binary
System
System.IO.Pipes
System.Runtime.Serialization.Json
System.CodeDom.Compiler
System.Linq
System.Runtime.Versioning
System.Collections
System.Linq.Expressions
System.Security
System.Collections.Concurrent
System.Net
System.Security.Authentication
System.Collections.Generic
System.Net.Cache
System.Security.Authentication.ExtendedProtection
System.Collections.ObjectModel
System.Net.Http
System.Security.Claims
System.Collections.Specialized
System.Net.Http.Headers
System.Security.Cryptography
System.ComponentModel
System.Net.Mail
System.Security.Cryptography.X509Certificates
System.ComponentModel.Design
System.Net.Mime
System.Security.Permissions
System.ComponentModel.Design.Serialization
System.Net.NetworkInformation
System.Security.Principal
System.Configuration.Assemblies
System.Net.Security
System.Text
System.Data
System.Net.Sockets
System.Text.RegularExpressions
System.Data.Common
System.Net.WebSockets
System.Threading
System.Data.SqlTypes
System.Numerics
System.Threading.Tasks
System.Diagnostics
System.Reflection
System.Timers
System.Diagnostics.CodeAnalysis
System.Reflection.Emit
System.Transactions
System.Diagnostics.Contracts
System.Resources
System.Windows.Input
System.Diagnostics.SymbolStore
System.Runtime
System.Xml
System.Diagnostics.Tracing
System.Runtime.CompilerServices
System.Xml.Linq
System.Drawing
System.Runtime.ConstrainedExecution
System.Xml.Resolvers
System.Dynamic
System.Runtime.ExceptionServices
System.Xml.Schema
System.Globalization
System.Runtime.InteropServices
System.Xml.Serialization
System.IO
System.Runtime.InteropServices.ComTypes
System.Xml.XPath
System.IO.Compression
System.Runtime.Serialization
System.Xml.Xsl
System.IO.IsolatedStorage
System.Runtime.Serialization.Formatters
All the foundational APIs
~37k APIs in .NET Standard 2.0

8. Versions of .NET Standard
Don’t worry about it.
Start with .NET Standard 2.0.

9. .NET Standard is also Open Source!
Next version is planned here:

10. Minimum requirement Visual Studio 2017 .NET Framework 4.7.2
.NET Core 2.1

11. Create a .NET Standard project

13. DEMO CodeSanook.VersionNumberToVersionCode

14. Compile against netstandard.dll
All APIs in netstandard.dll

15. Build output

16. Use your .NET Standard class library

17. DEMO Use your .NET Standard library in your .NET Framework

18. DEMO Use your .NET Standard library in your .NET Core

19. Under the hood

20. .NET Standard under the hood with .NET Framework
4/3/2019 5:57 PM
.NET Standard under the hood with .NET Framework
YOUR .NET Framework APPLICATION
.NET Framework ASSEMBLIES
TYPE
FORWARDING
Common language runtime handle type forwarding
YOUR .NET Standard CLASS LIBRARY
NETSTANDARD.DLL
This happens when you load .NET Standard-based library
© 2014 Microsoft Corporation. All rights reserved. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

21. netstandard.dll in .NET Framework
C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.7.2\Facades

22. Launch ILDASM tool
C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC>ildasm.exe
C:\Program Files (x86)\Microsoft SDKs\Windows\v10.0A\bin\NETFX Tools

24. .NET Standard under the hood with .NET Core
4/3/2019 5:57 PM
.NET Standard under the hood with .NET Core
YOUR .NET Core APPLICATION
.NET Core ASSEMBLIES
TYPE
FORWARDING
Common language runtime handle type forwarding
YOUR .NET Standard CLASS LIBRARY
NETSTANDARD.DLL
This happens when you load .NET Standard-based library
© 2014 Microsoft Corporation. All rights reserved. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

25. netstandard.dll in .NET Core
C:\Program Files\dotnet\shared\Microsoft.NETCore.App\2.1.5

27. Q & A http://codesanook.com https://fb.com/codesanookpage
Aaron Amm Theeranit