c# - Cannot find JavaScriptSerializer in .Net 4.0

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Top 5 Answer for c# - Cannot find JavaScriptSerializer in .Net 4.0

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Check if you included the .net 4 version of System.Web.Extensions - there's a 3.5 version as well, but I don't think that one works.

These steps work for me:

  1. Create a new console application
  2. Change the target to .net 4 instead of Client Profile
  3. Add a reference to System.Web.Extensions (4.0)
  4. Have access to JavaScriptSerializer in Program.cs now :-)
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  1. Right click References and do Add Reference, then from Assemblies->Framework select System.Web.Extensions.
  2. Now you should be able to add the following to your class file:
    using System.Web.Script.Serialization; 
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From the first search result on google:


JavaScriptSerializer Class

Provides serialization and deserialization functionality for AJAX-enabled applications.

Inheritance Hierarchy



Namespace: System.Web.Script.Serialization

Assembly: System.Web.Extensions (in System.Web.Extensions.dll)

So, include System.Web.Extensions.dll as a reference.

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I'm using Visual Studio 2015 and finally ran across this post.

Yes in order to use

JavaScriptSerializer json = new JavaScriptSerializer(); 

You must right click on references and under Assemblies --> Framework choose


Then add in your reference

using System.Web.Script.Serialization; 
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This is how to get JavaScriptSerializer available in your application, targetting .NET 4.0 (full)

using System.Web.Script.Serialization; 

This should allow you to create a new JavaScriptSerializer object!

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