The type or namespace name 'Json' does not exist in the namespace 'System' (are you missing an assembly reference?)

问题

I am using .NET Framework 4.5 and I'm having this issue. The type or namespace 'Json' does not exist in the namespace 'System'

So, I tried to Install-Package System.Json -Version 4.0.20126.16343 but I had this issue afterwards.

The type 'System.Uri' is defined in an assembly that is not referenced. You must add a reference to assembly 'System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'

Source: https://www.nuget.org/packages/System.Json

Any ideas would be really appreciated!

回答1:

That package is discontinued and shouldn't be used any more.

If you have a console application, I could recommend two options:

• JSON.NET. Not a part of the .NET Framework itself, but much faster than Microsofts implementation;
• Microsofts implementation of the JavaScriptSerializer.

Both are capable of reading and writing JSON. I find the JSON.NET library easier to use and more feature complete.

回答2:

using Newtonsoft.Json; Should get the job done

now you can use :
JsonConvert.SerializeObject JsonConvert.DeserializeObject

来源：https://stackoverflow.com/questions/30863514/the-type-or-namespace-name-json-does-not-exist-in-the-namespace-system-are