Mac Visual Studio Xamarin-类型或名称空间“ Linq”在名称空间“系统”中不存在（您是否缺少程序集引用？）

Question

On Mac Visual Studio - Xamarin Project, I get an error:

• the type or namespace 'Linq' does not exist in the namespace 'System' (are you missing an assembly reference)

I have tried to resolve it by using the nuget package manager. Specifically, click 'Packages' folder and click 'Add Packages...' and add Linq. Yet it still does not find Linq when I write 'using System.Linq' yet I can see 'System.linq' in the package folder under the project.

Tried : Refresh, Update, turn off and on

Why can't it find and use the package?

Edit: For similiar error 'HttpStatusCode' where it not found under 'System.Net' yet I have the dll (Version 2.0.5.0) found. I tried to install a new nuget package for it, System.Net.Primitives (Version 3.0.9.0) where 'HttpStatusCode' is stored under this new version. When I reference System.Net.Primitives it does not work.

Example:

'\\ The type or namespace name 'Primitives' does not exist in the namespace 'System.Net'
Using System.Net.Primitives;
Using System.Net;
namespace code {
 public class Example
 {
  \\ the type or namespace 'HttpStatusCode' could not be found
  public HttpStatusCode HttpResponse; 
 }
}`

Answer 1

In one of my project I solved it by following way:

Open solution explorer. Right click references, Click on assemblies, select system.xml.linq.

Add the reference assembly to the project. Clean and rebuild. It should serve the purpose.

Answer 2

Add this .nuget to your Solution. Micosoft.Net.Http.

Answer 3

您只需要将System.Core添加到您的References 。