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JavaScriptTypeResolver Class

Provides the abstract base class for implementing a custom type resolver.

Namespace:  System.Web.Script.Serialization
Assembly:  System.Web.Extensions (in System.Web.Extensions.dll)

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public abstract class JavaScriptTypeResolver

The JavaScriptTypeResolver class provides the services for:

  • Converting managed type information to a string value through the ResolveTypeId method.

  • Resolving a string value back to the appropriate managed type through the ResolveType method.

When the JavaScriptSerializer object serializes custom types, it can optionally include in the serialized JavaScript Object Notation (JSON) string a value that contains type information. During deserialization, JavaScriptSerializer can then reference this string value to determine the appropriate managed type to which the JSON string will be converted.

If you provide a type resolver to the JavaScriptSerializer instance, the serializer will use the ResolveTypeId and ResolveType methods to map between the managed type and the string value during the serialization and deserialization process, respectively.

The JavaScriptTypeResolver class is the base class for the SimpleTypeResolver class, which provides an implementation of a type resolver that uses the managed type assembly-qualified name.

Notes to Inheritors:

When you implement a type resolver, the string that is returned by the ResolveTypeId method must map back to the same managed type when the string value is passed to the ResolveType method.

The following example demonstrates how to create a custom type resolver.

public class CustomTypeResolver : JavaScriptTypeResolver
    public override Type ResolveType(string id)
        return Type.GetType(id);

    public override string ResolveTypeId(Type type)
        if (type == null)
            throw new ArgumentNullException("type");

        return type.Name;


Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5