All Questions
7,265
questions
2893
votes
13
answers
426k
views
What are the correct version numbers for C#?
What are the correct version numbers for C#? What came out when? Why can't I find any answers about C# 3.5?
This question is primarily to aid those who are searching for an answer using an incorrect ...
1019
votes
15
answers
238k
views
What is the difference between .NET Core and .NET Standard Class Library project types?
In Visual Studio, there are at least three different types of class libraries you can create:
Class Library (.NET Framework)
Class Library (.NET Standard)
Class Library (.NET Core)
While the first ...
- 28.8k
724
votes
31
answers
393k
views
How to check if a number is a power of 2
Today I needed a simple algorithm for checking if a number is a power of 2.
The algorithm needs to be:
Simple
Correct for any ulong value.
I came up with this simple algorithm:
private bool ...
- 41.2k
429
votes
11
answers
216k
views
What's the difference between .NET Core, .NET Framework, and Xamarin?
Microsoft now has .NET Core, .NET Framework and Xamarin (Mono) in its family.
It seems to be a lot of overlap here. What's the difference between these types of .NET Platforms? When should I choose to ...
- 4,327
344
votes
11
answers
135k
views
What is ".NET Core"?
Recently in an official .NET Framework Blog it was announced that .NET Core is going open source.
Ironically, the author mentions that what .NET Core is will be explained in the next post. Some more ...
- 34.5k
338
votes
8
answers
189k
views
.NET Core vs Mono
What is the difference between .NET Core and Mono?
I found a statement on the official site that said: "Code written for it is also portable across application stacks, such as Mono."
My goal is to ...
- 4,938
291
votes
10
answers
961k
views
How to remove item from list in C#?
I have a list stored in resultlist as follows:
var resultlist = results.ToList();
It looks something like this:
ID FirstName LastName
-- --------- --------
1 Bill Smith
2 John ...
- 45.2k
282
votes
7
answers
42k
views
.NET Standard vs .NET Core
I have read about the difference between .NET Standard and .NET Core, but I really don't know what the difference is, or when to choose a .NET Standard library project and when to choose a .NET Core ...
- 18.7k
238
votes
14
answers
381k
views
Automatically set appsettings.json for dev and release environments in asp.net core?
I've defined some values in my appsettings.json for things like database connection strings, webapi locations and the like which are different for development, staging and live environments.
Is there ...
- 22.5k
214
votes
12
answers
93k
views
Should I take ILogger, ILogger<T>, ILoggerFactory or ILoggerProvider for a library?
This may be somewhat related to Pass ILogger or ILoggerFactory to constructors in AspNet Core?, however this is specifically about Library Design, not about how the actual application that uses those ...
- 179k
192
votes
11
answers
191k
views
Unable to resolve ILogger from Microsoft.Extensions.Logging
I've configured my console application's Main like so
var services = new ServiceCollection()
.AddLogging(logging => logging.AddConsole())
.BuildServiceProvider();
And then I try to use it ...
- 6,420
175
votes
6
answers
106k
views
Pros and cons of AppSettings vs applicationSettings (.NET app.config / Web.config)
When developing a .NET Windows Forms Application we have the choice between those App.config tags to store our configuration values. Which one is better?
<configuration>
<!-- Choice 1 --&...
- 89.3k
159
votes
2
answers
53k
views
What are .NET Platform Extensions on docs.microsoft.com?
There is a framework-level navigation element at Microsoft Docs called ".NET Platform Extensions". It contains docs on recently added APIs like System.IO.Pipelines and System.Threading.Channels for ...
- 3,513
156
votes
2
answers
8k
views
If (false == true) executes block when throwing exception is inside
I have a rather strange problem that is occurring.
This is my code:
private async Task BreakExpectedLogic()
{
bool test = false;
if (test == true)
{
Console.WriteLine("Hello!");
...
- 6,699
144
votes
5
answers
68k
views
How to consume a Scoped service from a Singleton?
How should I inject (using .NET Core's built-in dependency injection library, MS.DI) a DbContext instance into a Singleton? In my specific case the singleton is an IHostedService?
What have I tried
I ...
- 75.6k
140
votes
14
answers
138k
views
What replaces WCF in .Net Core?
I am used to creating a .Net Framework console application and exposing a Add(int x, int y) function via a WCF service from scratch with Class Library (.Net Framework). I then use the console ...
- 2,897
134
votes
3
answers
64k
views
I'm lost. What happened to ASP.NET MVC 5?
I've been keeping my head down working on various projects and apparently Microsoft has been busy making some big changes and it's confusing the hell out of me. ASP.NET Core first came onto my radar ...
- 12.9k
130
votes
22
answers
154k
views
Detected package downgrade warning (dotnet core, vs 2017)
I have just updated all my nuget packages for my solution (dotnet core 1.1 project).
I am now getting the following warnings and I don't really know what they mean.
Update: I am still getting ...
- 3,123
130
votes
3
answers
49k
views
Are async console applications supported in .NET Core?
At some point in time the CoreCLR supported async main entry points. See http://blog.stephencleary.com/2015/03/async-console-apps-on-net-coreclr.html
However both the following programs are not ...
- 16.3k
129
votes
19
answers
173k
views
Error NU1605 Detected package downgrade
I am experiencing the following NU1605 dependency errors in my netcoreapp2.0 console application:
NU1605 Detected package downgrade: System.Diagnostics.Debug from 4.3.0 to 4.0.11. Reference the ...
- 39.3k
127
votes
24
answers
175k
views
MSBUILD throws error: The SDK 'Microsoft.NET.Sdk' specified could not be found
I'm trying to build a solution using msbuild command line and I keep getting this error:
error MSB4236: The SDK 'Microsoft.NET.Sdk' specified could not be found.
The version of msbuild is the latest ...
- 1,291
123
votes
6
answers
51k
views
No AppDomains in .NET Core! Why?
Is there a strong reason why Microsoft chose not to support AppDomains in .NET Core?
AppDomains are particularly useful when building long running server apps, where we may want to update the ...
- 1,279
121
votes
25
answers
154k
views
The library hostpolicy.dll was not found
I have a simple .NET Core project (console app) that I'm trying to compile and run. dotnet build succeeds, but I get the following error when I do dotnet run:
dotnet run
Project RazorPrecompiler (....
- 52.3k
119
votes
4
answers
139k
views
System.ServiceModel not found in .NET Core project
I have a .NET Core xUnit project. I'm trying to call a WCF service from it but get the following exception:
System.InvalidOperationException occurred
HResult=0x80131509
Message=An error occurred ...
- 28k
117
votes
39
answers
259k
views
EF Core add-migration Build Failed
I have a developer that is getting "Build failed." when running add-migration in a .NET Core EF project, with no explanation of why the build failed. How do you troubleshoot this error?
This is what ...
- 1,789
110
votes
19
answers
178k
views
The current .NET SDK does not support targeting .NET Core 2.1. Either target .NET Core 2.0 or lower, or use a .NET SDK that supports .NET Core 2.1
have tried upgrading to the professional version of visual studio 2017 v 15.6.0 (Preview 7.0)
and installed aspnetcore-runtime-2.1.0-preview1-final-win-x64 and .net core SDK 2.1.4.
When I created a ...
- 1,292
105
votes
4
answers
76k
views
Net Core API: Purpose of ProducesResponseType
I want to understand the purpose of ProducesResponseType.
Microsoft defines as:
a filter that specifies the type of the value and status code returned by the action.
So I am curious what are ...
user11973685
102
votes
24
answers
140k
views
Is there an easy way to check the .NET Framework version?
The problem is that I need to know if it's version 3.5 SP 1. Environment.Version() only returns 2.0.50727.3053.
I found this solution, but I think it will take much more time than it's worth, so I'm ...
- 25.8k
99
votes
4
answers
57k
views
dotnet core System.Text.Json unescape unicode string
Using JsonSerializer.Serialize(obj) will produce an escaped string, but I want the unescaped version. For example:
using System;
using System.Text.Json;
public class Program
{
public static void ...
- 1,399
97
votes
9
answers
22k
views
The author primary signature's timestamp found a chain building issue: UntrustedRoot: self signed certificate in certificate chain
While doing a docker build on my .NET Core project, I got the following error on all my NuGets:
80.19 /app/GradingTool.Tests/GradingTool.Tests.csproj : error NU3028: Package 'Microsoft....
- 1,405
96
votes
4
answers
58k
views
Package version is always 1.0.0 with dotnet pack
TLDR: Where is dotnet pack pulling the version information when it creates the nuget package for an assembly?
I have a library, that I had transitioned from a .NET 4.6.1 project to a .NET Core ...
- 1,808
96
votes
4
answers
69k
views
dotnet restore warning NU1701
I am using .NET Core with C#, and when I did dotnet restore, it gave the following error:
PS C:\workspace\Arbitrator> dotnet restore
C:\workspace\Arbitrator\Arbitrator.csproj : warning NU1701: ...
- 13.5k
96
votes
9
answers
213k
views
Add client certificate to .NET Core HttpClient
I was playing around with .NET Core and building an API that utilizes payment APIs. There's a client certificate that needs to be added to the request for two-way SSL authentication.
How can I achieve ...
- 1,183
94
votes
7
answers
54k
views
Using Razor outside of MVC in .NET Core
I would like to use Razor as a templating engine in a .NET console application that I'm writing in .NET Core.
The standalone Razor engines I've come across (RazorEngine, RazorTemplates) all require ...
- 1,914
91
votes
10
answers
200k
views
Cannot access a disposed object. A common cause of this error is disposing a context
I have written a simple application and when I navigate to my edit page the below error pops up.
Microsoft.EntityFrameworkCore.Query[10100]
An exception occurred while iterating over the results of ...
- 1,350
88
votes
18
answers
178k
views
Could not load file or assembly Microsoft.Extensions.DependencyInjection.Abstractions, Version=1.1.0.0
After update to the new package Microsoft.EntityFrameworkCore.SqlServer 1.1.2 I got error when try to create DBContext:
System.IO.FileLoadException occurred HResult=0x80131040
Message=Could ...
- 1,249
85
votes
3
answers
25k
views
Difference between ASP.NET Core (.NET Core) and ASP.NET Core (.NET Framework)
What is the difference between ASP.NET Core Web (.NET Core) vs ASP.NET Core Web (.NET Framework)?
and does .NET Framework provide similar performance as to .NET Core?
- 3,769
85
votes
2
answers
5k
views
Why is code behavior different in release & debug mode?
Consider the following code:
private static void Main(string[] args)
{
var ar = new double[]
{
100
};
FillTo(ref ar, 5);
Console.WriteLine(string.Join(",", ar.Select(a =&...
- 1,942
82
votes
10
answers
293k
views
instance of entity type cannot be tracked because another instance with same key value is tracked [closed]
I'm using generic repository pattern in asp.net core 2.0 which can not dispose repository object, when I am going to update the entry its updated for one time successfully but when I am trying to ...
- 1,051
82
votes
5
answers
63k
views
How do I exclude files/folders from a .NET Core/Standard project?
In .NET Core and .NET Standard projects, if you put files and folders within the project directory, they are automatically picked up by Visual Studio; essentially they are part of the project.
What ...
- 28.8k
82
votes
2
answers
29k
views
What is project.lock.json?
I followed the instruction to create new .NET Core project and ran this from cmd:
dotnet new
dotnet restore
The second statement creates project.lock.json that contains a lot of garbage (not really ...
- 43.5k
81
votes
7
answers
45k
views
What's the difference between ASP.NET 5, .NET Core, and ASP.NET Core 5? [closed]
I'm confused on the distinction between these terms:
ASP.NET 5 (now renamed ASP.NET Core and released as 1.0, not 5.0)
ASP.NET Core 5
.NET Core
Can anyone briefly explain it?
- 1,150
80
votes
5
answers
31k
views
Build .exe file in .NET Core RC2
Every time I build a project using the new .NET Core RC2 templates I am not provided with a runnable .EXE file. If I hit F5 for debugging my console application it runs fine through the
C:\Program ...
- 1,258
78
votes
3
answers
100k
views
How to extract custom header value?
I have this exact code from the accepted answer in my project which I need to migrate into ASP.NET Core MVP.
How to extract custom header value in Web API message handler?
var env = Request.Headers....
- 3,859
78
votes
4
answers
54k
views
How do I reference a .NET Framework project in a .NET Core project?
I'd really like to start using .NET Core and slowly migrate applications and libraries to it. However, I can't realistically upgrade my entire code base to use .NET Core and then go through the ...
- 25.2k
78
votes
2
answers
33k
views
What's the difference between the new netstandardapp and netcoreapp TFMs?
I noticed that NuGet has recently added support for several new TFMs related to .NET Core, including:
netstandard (1.0-1.5)
netstandardapp (1.5)
netcoreapp (1.0)
To the best of my knowledge, ...
- 33.4k
73
votes
8
answers
52k
views
TimeZoneInfo in .NET Core when hosting on unix (nginx)
For example, when I try to do the following.
TimeZoneInfo.FindSystemTimeZoneById("Central European Standard Time")
I get the error, that the TimeZone is not available on the local computer. When I ...
- 1,133
69
votes
1
answer
58k
views
Difference between AllowedHosts in appsettings.json and UseCors in .NET Core API 3.x
I see that .NET Core 3.x comes with a new special configuration AllowedHosts used to list hosts allowed to access the site while this option already exists with CORS (app.UseCors).
What's the ...
- 793
69
votes
4
answers
101k
views
How to run all tests in Visual Studio Code
The latest version of VS Code already provides an easy way of running a single test as pointed on Tyler Long's answer to the question Debugging xunit tests in .NET Core and Visual Studio Code.
However,...
- 9,043
68
votes
3
answers
15k
views
No UseDatabaseErrorPage() extension method in Net Core 3.0
I have created Net Core 3.0 app and following code that worked in 2.2 now is not.
app.UseDatabaseErrorPage();
Looks like in 3.0 class DatabaseErrorPageExtensions does not exist within Microsoft....
- 1,130