Package ‘Microsoft.PortableLibrary.TargetingPack.Msi.Resources,version=15.0.26621.2,language=en-US’ failed to install

While updating and later uninstalling Visual Studio 2017 i got error: Package ‘Microsoft.PortableLibrary.TargetingPack.Msi.Resources,version=15.0.26621.2,language=en-US’ failed to install


log file:


After few hours of fruitless search of solutions i was able to correct problem by removing package “Microsoft Portable Library Multi-Targeting Pack – enu”

Removing “Microsoft Portable Library Multi-Targeting Pack Language Pack – enu” package using Windows Installer Clean Up








To remove it from Windows 10 i used Windows Installer Clean Up Utility that can be downloaded from:



Then next set of errors appeared:

It appears that “Windows Phone SDK 8.0 Assemblies for Visual Studio 2017” and “IIS 10.0 Express” are producing problems.

So back to Windows Installer Clean Up Utility











Another error pops up:

So next thing I tried is to remove both Web deploy packages.








Unfortunately that did not work ­čÖü


So i went to the Microsoft site:

and downloaded x64 version of WebDeploy 3.6 and installed it

That did not help either

new log file:

This one lead me to fixing registry. Here is a list of Guids that my account seem to have lost permission for:

Remember to add permission to Administrators group!






Few of them are missing but it will take you a few installation restarts to find them.






Parameterizing Unit Tests using xUnit

xUnit allows our unit test to use parameters, which allows us to test our code for multiple scenarios without needing to write multiple methods with same content.

Let’s look at example from previous lesson

Here we test if 3 + 9 equals 12.

But what if we wanted to test our Add method for multiple scenarios?


We could use InlineData Attribute.

InlineData Attribute allows us to run our test with input parameters, and passes those parameters to test method using params object[] data.

We are not done yet.

Compiler is not happy and we are getting error : Fact methods cannot have parameters.

Simple solution is to replace Fact Attribute with Theory Attribute

Now, when we run our unit test we can see that same test method ran 3 times an all test have passed┬á ­čÖé

Also note that we can also see input parameters!

Beginners guide to xUnit

To add xUnit to your project open up NuGet package manager

(Tools -> NuGet Package manager -> Manage Nuget packages for Solution


Right-click References of your project and chose Manage Nuget packages)

xUnit Nuget installation





And find xUnit package by  James Newkirk and Brad Wilson and press install.

To use xUnit in your project you do not have to decorate your class with TestClass attribute!

You must only decorate your methods with Fact Attribute.

Also be sure to reference┬áXunit assembly in your class file because xUnit’s Assert class is from that namespace.

If tests you write do not show in Test explorer, open NuGet  packet manager and add xunit.runner.visualstudio package (do not be confused if you see Visual Studio 2012+ in description, it is just saying that this is for version from VS 2012 an onwards).

There is also neat trick to modify name of your tests. By default Test explorer is showing xUnit’s test names in format Class.Method, but you can only display test Method names. Add new json file to root of project and name it “xunit.runner.json” and open properties of that file and under “Copy to Output Directory”┬á option chose “Copy if newer”.













Open under xunit.runner.json file and under Schema input “”, then inside brackets type “methodDisplay”: “method”.





Happy unit testing ­čÖé

How to create Unit Test with VisualStudio 2017

This brief tutorial will show you how to create Unit Test with VisualStudio 2017.

There are a few ways to create unit test using VS 2017.

1) Create unit test From the class

Create new Console Application

And in a Program class add public method.

Right click on a method and chose “Create Unit Tests”.

How to add an Unit test project from a class.







Be sure to add a public method because without it you will get an error:

Create Unit Tests is supported only within a public class or a public method

An error is pretty straight forward ­čÖé

"Create Unit Tests is supported only within a public class or a public method" error.

Error you get when adding Unit test project from an empty class or class that has only static members.





Then you can chose additional options or additional Testing frameworks

Unit test options






2) Manually adding a test project

Create new method that returns string with value test.

Right click solution and add Unit Testing project

Choosing unit test project







Then add an reference to project you wish to unit test

And create a new class ProgramTests

Decorate class with a [TestClass] Attribute

Also add a ShouldReturnTestString void method decorated with a [TestMethod] Attribute

Be sure to add those Attributes because without them you will not be able to run unit test. Give it a shot.


DataContractSerializer made its first appearance with release of WCF but can operate outside WCF.

DataContractSerializer can serialize types decorated with DataContract, MessageContract, Serializable attributes, types that implement IXmlSerialisable and all public types without Attributes.

During serialization Reference integrity is by default not preserved. You can preserve it by setting “IsReference = true” to DataContract attribute. Note that this approach my cause problems if DataContractSerializer is not serializer who will deserialize data.


You can also use OnSerializing, OnSerialized, OnDeserializing, OnDeserialized Attributes to fine-grain your serialization process.

This tutorial will explain how to serialize and deserialize types by decorating type with DataContract attribute.

First we use need to add reference to System.Runtime.Serialization. Secondly we decorate the type with DataContract Attribute, and inside type wee decorate fields and properties with DataMember Attribute. Then we instantiate DataContractSerializer instance and use its WriteObject and ReadObject methods to serialize/deserialize data.

Example of DataContractSerializer:

By using DataMember Attribute we can serialize automatic properties, because property itself will be serialized and not its backing field.

Because DataContractSerializer does not store type and assembly information we need to tell it which is the type we wish to serialize by specifying type in the DataContractSerializer constructor.

As no type or assembly information are preserved be sure to supply KnownType  Attribute to your base class to be able to use inheritance properly.


Data Contract Serializer


You can download solution from this link.

To return to other serialization techniques return to this location.

Binary serialization

Today’s topic is Binary serialization, if you wish to read more about serialization or other types of serialization please visit this link:

Binary serialization is type of serialization where type fidelity and reference integrity are preserved, meaning assembly information, private and public fields are being preserved as well as theirs memory locations. You would normally use binary serialization to preserve application state, store it to a backing store (storage medium) and use it later to run application on same computer or maybe multiple other computers.

Hearth of binary serialization is BinaryFormatter class and its Serialize and Deserialize methods. Serialize and Deserialize  methods take two parameters stream and object graph and serialize or deserialize object accordingly. Result of serialization are unreadable to human eye but you can read some information:

Binary Formatter

BinaryFormatter serialization result

As you can see type and field information are preserved.

If you wish serialized data in more readable way you can use SoapFormatter. Note that SoapFormatter is obsolete so use it only for debugging and testing purposes.


SoapFormatter serialization result

To mark a type serializable use Serializable attribute to decorate type. Serializable attribute is not inherited so if you wish to serialize both base and derived class decorate both of them with serializable attribute. Other approach would be to implement ISerializable interface.

If you wish not to serialize filed add NonSerialized attribute.

You can serialize null types, but you can not serialize or deserialize null streams.

Properties are not serialized but their private fields are. Do not serialize auto implemented properties because you cannot guarantee that theirs private fields will have the same name on the other machines as they do on yours.

If we wish more control during Serialization/Deserialization processes we can use attributes from System.Runtime.Serialization and apply them to the methods.
Attributes we can use for methods during serialization:
OnSerializingAttribute – use this attribute to prepare data before deserializing . For example encrypt password field or change distance from miles to kilometers.
OnSerializedAttribute – restores type to a status it was before applying OnSerializingAttribute.

Attributes we can use for methods during serialization:
OnDeserializingAttribute – because serialization cannot use constructor, use this attribute for method that will simulate constructor, and maybe set fields to default values.
OnDeserializedAttribute – use this attribute to manually set value of the fields just after serialization process has finished.


Example for Binary serialization.

We will try to serialize data from Employee class:



Download link for entire solution is here.

´╗┐Serialization and Deserialization

Serialization is the process of transforming an object or object graph
into a stream of bytes or text. Similarly,  deserialization is the process of transforming bytes into an object or object graph.

Object graph: In computer science, in an object-oriented program, groups of objects form a network through their relationships with each otherÔÇöeither through a direct reference to another object or through a chain of intermediate references. These groups of objects are referred to as object graphs.

So, object graph can be a single List of string, entire class or even state of application.

Usage of serialization can wary, weather you want to communicate between two applications on one PC, save state of an Application on your local hard-drive or maybe in cloud… possibilities are endless.

What can I serialize?

You cannot serialize methods or delegates, but you can serialize fields and properties. That is why we can use DTO models (Data transferable models). DTO models are classes with properties that represent data that we want to represent. You have seen some examples so far, like Employee class.

To make this class more readable you could just add DTO suffix after Employee and everybody would know that this is an DTO class.

We will inspect how to serialize and deserialize data by using:

  1. Binary serialization,
  2. Custom serialization,
  3. XML Serializer,
  4. JSON Serializer,
  5. Data Contract Serializer

Among these XML Serializer and JSON Serializer are the most common ones but as we progress between each one of them you will see that other serialization mechanisms have their usage.


Preprocessor Directives

Preprocessor directives are instructions that we give to the compiler and compilers job is to compile code based on those instructions.

All preprocessor directives must begin with hash(#) sign, but do not need to end with semicolon(;) because they are not statements.

Preprocessor directives are not inherited and are file specific.

List of preprocessor directives:

#pragma warning
#pragma checksum

Continue reading

WinMD Assembly

Windows 8 introduced WinRT(Windows Runtime) that allows us to develop applications based on C++, C#, Vb and JavaScript by allowing access to its Api and by allowing communication between different programming languages. Communication between languages is possible through Windows Runtime Component that creates WinMD Assembly. WinMD Assembly is a Assembly that contains metadata but can also contain types.

When you try to create Windows 8.1 store app you cannot add usual Class Library, you have to add Windows Runtime Component and there you can write your usual code.

Trying to add Class library to your Store App will result in “Unable to add a reference to project” error.

WinMD limitations (copied from

  • The fields, parameters, and return values of all the public types and members in your component must be WinRT types.
  • Public structures may not have any members other than public fields, and those fields must be value types or strings.
  • Public classes must be sealed. If your programming model requires polymorphism, you can create a public interface and implement that interface on the classes that must be polymorphic. The only exceptions are XAML controls.
  • All public types must have a root namespace that matches the assembly name, and the assembly name must not begin with ÔÇťWindows.ÔÇŁ

Why would I need to create WinMD class library?

Lets explore it through Windows store app example.

Create new Solution and there add two Blank App.s for Windows 8.1 (one for C# and another for JS).

Both of these apps should have:

2x Textbox

1x Label

2x Button

Goal of this Application is to create Application where you can input data inside two different TextBoxes and combine their values inside Label after clicking button. Second goal is to copy some text value in your clipboard(simply copy some text with Ctrl+C) and display value in Label after clicking second button.

All this code can be easily achieved by writing it in backend of MainPage.xaml.cs file or inside JavaScript function, but we want our Application to share code, and that is here WinMD steps in. You can create methods that perform that actions and reuse it across different applications and different languages. Yup, even JavaScript can use WinMD classes written in C#.

Example of WinMD / Windows Runtime Component Assembly



MainPage.xaml.cs – Buttons

Windows Runtime Component – Helper class

If you wish to inspect entire solution , download it from this link.

Please do not use code from solution  for your projects because no checks were implemented what so ever.


GAC (Global Assembly Cache)

You can locate GAC folder inside Windows directory. GAC folder contains only strongly named assemblies. All applications that are running on your machine can access GAC folder and use its assemblies. Benefits of storing strongly named assemblies inside GAC are:

  • There is no need to distribute that particular assembly with every new version of application
  • Assemblies stored in GAC folder are strongly named so you need not to worry about having two or more version of same assembly distributed.

How can i locate GAC folder?

There are actually two locations:

  1. Location for assemblies created with .Net Framework 2.0 to .Net Framework 3.5
  2. Location for assemblies created with .Net Framework 4.0 and newer

Usually you cal locate it by typing C:\Windows\assembly for older strongly named assemblies or C:\Windows\Microsoft.NET\assembly for newer strongly named assemblies.

If your machine is not installed on C drive or your windows folder is not named Windows simply type in File explorer : %WINDIR%\Assembly or %WINDIR%\Microsoft.NET\assembly and you there you can find GAC folder.

How to install Strongly named assembly inside Global Assembly Cache?

Add new Class library project to Solution and name it AssemblyToInstall and strong name it.

Drag and drop approach:

Just simple locate bin\Debug folder inside AssemblyToInstall project, locate AssemblyToInstall.dll file and drop it to appropriate location (C:\Windows\Microsoft.NET\assembly). Note that you can do this only if your user has elevated privileges.

Using GacUtil.exe

If you are using Visual Studio 2013 or 2015 version, you can search for Developer Command Prompt and run it as Administrator.

New console will open.

Navigate to project. Mine is located on D drive under charp folder

Next you will need to run gacutil toll with -i parameter (basically -i switch is telling gacutil that we want to install assembly) followed by Assembly dll we want to install.

run command: gacutil.exe -i AssemblyToInstall.dll


How to use gacutil to install strongly named assembly inside GAC folder

You should receive message: “Assembly successfully added to the cache”

If you receive message: “Failure adding assembly to the cache: Attempt to install an assembly without a strong name”. That means that you have not signed assembly.

Now navigate to %WINDIR%\Microsoft.NET\assembly\GAC_MSIL\AssemblyToInstall and there you can see your assembly and can use that path to provide reference to that assembly to all applications located on this machine.

Tomorrow we will continue with topic on how to implement side-by-side hosting.

© 2018 LearnC#WithDarko

Theme by Anders NorenUp ↑