DotNet – ../blog

C# Version History

Version	.NET Framework	Visual Studio	Important Features
C# 1.0	.NET Framework 1.0/1.1	Visual Studio .NET 2002	Basic features

C# 2.0	.NET Framework 2.0	Visual Studio 2005	Generics
			Partial types
			Anonymous methods
			Iterators
			Nullable types
			Private setters (properties)
			Method group conversions (delegates)
			Covariance and Contra-variance
			Static classes

C# 3.0	.NET Framework 3.0\3.5	Visual Studio 2008	Implicitly typed local variables
			Object and collection initializers
			Auto-Implemented properties
			Anonymous types
			Extension methods
			Query expressions
			Lambda expressions
			Expression trees
			Partial Methods

C# 4.0	.NET Framework 4.0	Visual Studio 2010	Dynamic binding (late binding)
			Named and optional arguments
			Generic co- and contravariance
			Embedded interop types

C# 5.0	.NET Framework 4.5	Visual Studio 2012/2013	Async features
			Caller information
C# 6.0	.NET Framework 4.6	Visual Studio 2013/2015	Expression Bodied Methods
			Auto-property initializer
			nameof Expression
			Primary constructor
			Await in catch block
			Exception Filter
			String Interpolation
C# 7.0	.NET Core 2.0	Visual Studio 2017	out variables
			Tuples
			Discards
			Pattern Matching
			Local functions
			Generalized async return types
			Expanded expression body members

C# 8.0	.NET Core 3.0	Visual Studio 2019	Readonly members
			Default interface methods
			Using declarations
			Static local functions
			Disposable ref structs
			Nullable reference types

			Exception Filter
			String Interpolation

C# 9.0	.NET 5.0	Visual Studio 2019	Records
			Init-only properties
			Top-level statements
			Init accessors and readonly fields
			With-expressions
			Value-based equality
			Inheritance changes

C# 10.0	.NET 6.0	Visual Studio 2022	Record structs
			Global using directives
			File-scoped namespace declaration
			Extended Proptery Patterns
			Null Parameter Checking
			Constant interpolated strings

.NET: Roslyn Has a Missing Path

This error seems to occur when I am opening an upgraded web project in Visual Studio 2019:

This happens when the current codebase is using older VS2015 templates.

The simplest approach is to open NuGet’s Package Configuration Console in Visual Studio and enter the following to upgrade the compiler:

Update-Package Microsoft.CodeDom.Providers.DotNetCompilerPlatform -r

REFERENCE:

https://stackoverflow.com/questions/32780315/could-not-find-a-part-of-the-path-bin-roslyn-csc-exe

.NET: How To Use ViewData, ViewBag And TempData in MVC

ViewData

It is a dictionary which can contain key-value pairs where each key must be string. We can use it in transferring data from Controller to View. We can only transfer data from Controller to view but if we wish to pass data back again to controller then it is not possible. So it is valid only for the current request.

ViewBag

ViewBag is also similar to ViewData. It is used to transfer data from Controller to View. It is a type of Dynamic object, that means you can add new fields to viewbag dynamically and access these fields in the View. You need to initialize the object of viewbag at the time of creating new fields.

TempData

TempData is a dictionary object derived from TempDataDictionary. It is for subsequent HTTP requests; unlike ViewBag and ViewData, those stay only for current request. It can be used to maintain data between controller actions as well as redirects.

REFERENCES:

.NET: What Version Is On the Target Server

I’m upgrading .NET (legacy 4.*) applications on multiple unfamiliar servers. This includes needing to know if the currently installed framework meets my requirements. Instead of fumbling through the actual registry, I can pasted this C# snippet into a console app and all is good:

REFERENCE: https://docs.microsoft.com/en-us/dotnet/framework/migration-guide/how-to-determine-which-versions-are-installed

C# Access Modifiers

REFERENCE: https://www.geeksforgeeks.org/access-modifiers-in-c-sharp/

Access Modifiers are keywords that define the accessibility of a member, class or datatype in a program. These are mainly used to restrict unwanted data manipulation by external programs or classes. There are 4 access modifiers (public, protected, internal, private) which defines the 6 accessibility levels as follows:

public

protected

internal

protected internal

private

private protected

The Accessibility table of these modifiers is given below:

	public	protected	internal	protected internal	private	private protected
Entire program	Yes	No	No	No	No	No
Containing class	Yes	Yes	Yes	Yes	Yes	Yes
Current assembly	Yes	No	Yes	Yes	No	No
Derived types	Yes	Yes	No	Yes	No	No
Derived types within current assembly	Yes	Yes	No	Yes	No	Yes