When using json.net serialization object, a strange problem may be encountered: the object is dual serialization. This will cause JSON data to be wrapped in dual quotes in the response, and the embedded quotes are also righteous.

root cause

The root cause is the serialization method. If you use JSONCONVERT.SerializeObject (Instance)

JSONCONVERT.SERIALILILILILIALIEOBOCT (Instance). This is because you first serialize it into a string, and then the API controller will further serialize it to the JavaScript string word. solution

To solve this problem, you only need to return directly to the object: Public IenuMerable Getfoobars () {{ var foobars = ...; Return Foobars; }

public IEnumerable GetFoobars()
{
    var foobars = ...;
    return foobars;
}

: config.Formatters.jsonFormatter.serSettings.converters.add config.Formatters.jsonFormatter.Serializersettings.ConVerters.add (new barconverter ());

Make sure that the custom converter is correctly implemented.

config.Formatters.JsonFormatter.SerializerSettings.Converters.Add(new FooConverter());
config.Formatters.JsonFormatter.SerializerSettings.Converters.Add(new BarConverter());