How to create instance of an object?

Question

I am using Json.Net library to convert objects to json and back to objects.

I have an interface:

public interface IGoods
{
    List<IPen> Pens { get; set; }
    List<IPencil> Pencils{ get; set; }
    void Deserialize(String json);

}

implementation:

new public void Deserialize(String json)
    {
        JsonConvert.DeserializeObject<Goods>(json);
    }

The obvious error I got is: Could not create an instance of type Project.IPen. Type is an interface or abstract class and cannot be instantated.

How do I overcome this error?

Thanks!

possible duplicate of JSON.NET - how to deserialize collection of interface-instances? — nawfal
– nawfal, Commented Jul 20, 2014 at 12:03

Jonathan · Accepted Answer · 2010-12-20 22:48:17Z

1

According to the documentation you need to write some logic to tell Json.Net how to do the object creation - http://james.newtonking.com/projects/json/help/CustomCreationConverter.html

answered Dec 20, 2010 at 22:48

Jonathan

6,0031 gold badge29 silver badges35 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Community · Accepted Answer · 2017-05-23 12:04:14Z

0

See Using Json.NET converters to deserialize properties

edited May 23, 2017 at 12:04

CommunityBot

11 silver badge

answered Dec 20, 2010 at 22:42

devdigital

34.4k9 gold badges102 silver badges122 bronze badges

Comments

Greg Sansom · Accepted Answer · 2010-12-20 23:31:56Z

0

IPen is an interface, not a class, which means it cannot be instantiated. Basically what you need is a class which implements the IPen interface (let's call it Pen). You should then be able to replace IPen in the Json string with Pen, and Json.Net will be able to instantiate the object.

Just to be clear, your Pen class should look something like this:

public class Pen: IPen
{
//Interface implementation here.
}

answered Dec 20, 2010 at 23:31

Greg Sansom

20.9k6 gold badges61 silver badges77 bronze badges

Collectives™ on Stack Overflow

How to create instance of an object?

3 Answers 3

Comments

Comments

Comments

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

Comments

Linked

Related