Do I have .net 5.0 installed?

Question

i'm confused

windows 10, fully updated
visual studio 2022  (64-bit) V17.5.1 fully updated (just installed)

Do I have .net 5.0 installed?

the registery states v4.

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Net Framework Setup\NDP\CDF\v4.0
SMSvcHostPath    REG_SZ    C:\Windows\Microsoft.NET\Framework64\v4.0.30319\


if i run the dotnet command from the DOS command line it states i have v7 sdk.

C:\Users\hattie>dotnet --list-sdks
3.1.426 [C:\Program Files\dotnet\sdk]
5.0.408 [C:\Program Files\dotnet\sdk]
7.0.201 [C:\Program Files\dotnet\sdk]

what do i have do i need to update somehow?

the problem is.....

I am learnig c# using visual studio

The c# command isoweek needs .net 5 work?

I think i have v7 installed.... maybe not

i am trying to get the isoweek number using c# in VS (Windows Form).

so will v7 sdk work? I assume the v7 sdk was installed with the VS installation so i am assuming the isoweek command would work.

i don't seem to be able to get windows to update itself to .net 5 I found the vy sdk web page

in my c# code -
the     using System.Globalization; 

statement at the top of my VS windows Form is greyed out suggesting to me that it's not included/working/recognised!!!!
so i must still be on .net v4

the c# command in my code

System.Globalization.ISOWeek.GetWeekOfYear("18-03-2023");

has a lot of red lines under it suggesting it's not recognised.

but i have v7 sdk .net???

where do i go from here?


also
as an aside

if I have the statement 
using System.Globalization; 

at the top of my code do i need to use the command - 

System.Globalization.ISOWeek.GetWeekOfYear("03-03-2023");

or can i simplyfiy it to 

ISOWeek.GetWeekOfYear("03-03-2023"); 

I assume i can !!!!

thank you

Answer 1

Probably your project is based on .NET Framework, not on .NET 5. Then you should create a new project. For example, try a new “Windows Forms App” (not “Windows Forms App (.NET Framework)”. Use this code:

int week1 = System.Globalization.ISOWeek.GetWeekOfYear( DateTime.Today );
// or:
int week2 = System.Globalization.ISOWeek.GetWeekOfYear( new DateTime( 2023, 3, 3 ) );

The using statements are grayed when not needed (not used). If you add using System.Globalization, then you can simplify the function: ISOWeek.GetWeekOfYear(...).