"application/json" constant in .NET framework

Question

I've just declared a constant for the "application/json" content type in one of my classes.

public const string JsonContentType = "application/json";

I'm not sure it is a good practice.

Does .NET framework have a predefined const for "application/json"?

See http://stackoverflow.com/questions/1015892/is-there-an-enum-for-the-contenttype-property-on-a-httpwebresponse-text-plain — Andreas Adler, Dec 18 '13 at 10:46
Related post - [ASP MVC - Are there any constants for the default content types?](https://stackoverflow.com/q/10362140/465053) & [What is the correct JSON content type?](https://stackoverflow.com/q/477816/465053) — RBT, Feb 28 '19 at 04:57

score 193 · Answer 1 · answered Feb 12 '19 at 13:06

193

In order to add an up-to-date answer: since dotnet core 2.1 MediaTypeNames.Application.Json has been defined.

See https://github.com/dotnet/corefx/pull/26701 for the changeset.

answered Feb 12 '19 at 13:06

Bob Van de Vijver

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It looks like the `Json` constant isn't available in .NET Standard 2.0 though unfortunately. – Panzercrisis Apr 13 '20 at 16:03
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Please mark this as the best answer or update the best answer. – bruno.almeida Oct 29 '20 at 12:34
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same, this should be the proper correct answer – Alfred Severo Jan 16 '21 at 19:10

score 71 · Accepted Answer · edited Feb 06 '21 at 18:08

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See Newer Answer. This answer is now inaccurate.

While there are some MIME constants defined in MediaTypeNames (see here), there no constant for "application/json".

Putting additional content types in a shared const is probably best practice, better than defining them in string literals a million times throughout your code at least.

Plus it gives you the flexibility of using new/custom MIME types, which a specific .NET version might not have.

edited Feb 06 '21 at 18:08

Andy Joiner

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answered Dec 18 '13 at 10:47

Kevin

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Glad that you mentioned about defining a public const best practice. That's the #cleanCode way of doing it rather than littering your code here and there. – RBT Jan 09 '17 at 06:44
The implied conclusion that it "enables" new/custom MIME types does not hold as having a *string constant* defined does not preclude additions to the open set (all possible strings) accepted. Since JSON/XML/HTML are so ubiquitous on the internet, having these standard (in one of the several) .NET Net/Web assemblies would be useful.. I wonder if .NET Core changes this answer? – user2864740 Jun 12 '18 at 19:34
Arg, or, with the related answer.. if only "application/json" was added.. – user2864740 Jun 12 '18 at 20:07
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.NET Core 2.1.0 has the `MediaTypeNames.Application.Json` defined :) See https://github.com/dotnet/corefx/pull/26701. – Bob Van de Vijver Feb 12 '19 at 13:02

score 6 · Answer 3 · answered Feb 17 '22 at 02:43

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There is now for Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6...

System.Net.Mime.MediaTypeNames.Application.Json

answered Feb 17 '22 at 02:43

Mick

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"application/json" constant in .NET framework

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