Elasticsearch/NEST 6 - 将枚举存储为字符串

Question

是否可以在 NEST6 中将枚举存储为字符串？

我已经试过了，但似乎不起作用。有什么建议吗？

var pool = new SingleNodeConnectionPool(new Uri(context.ConnectionString));
connectionSettings = new ConnectionSettings(pool, connection, SourceSerializer());

    private static ConnectionSettings.SourceSerializerFactory SourceSerializer()
    {
        return (builtin, settings) => new JsonNetSerializer(builtin, settings,
            () => new JsonSerializerSettings
            {
                Converters = new List<JsonConverter>
                {
                    new StringEnumConverter()
                }
            });
    }

Answer 1

使用 StringEnumAttribute attribute在属性(property)上。这向内部序列化器发出信号，将枚举序列化为字符串。在使用它时，您不需要使用 NEST.JsonNetSerializer package

如果你想为所有枚举设置它，你可以这样做

private static void Main()
{
    var pool = new SingleNodeConnectionPool(new Uri("http://localhost:9200"));
    var connectionSettings = new ConnectionSettings(
        pool, 
        (builtin, settings) => new JsonNetSerializer(builtin, settings,
            contractJsonConverters: new JsonConverter[] { new StringEnumConverter() }));

    var client = new ElasticClient(connectionSettings);

    client.Index(new Product { Foo = Foo.Bar }, i => i.Index("examples"));
}

public class Product
{
    public Foo Foo { get;set; }
}

public enum Foo
{
    Bar
}

这会产生一个像

这样的请求

POST http://localhost:9200/examples/product
{
  "foo": "Bar"
}

我认为您尝试设置转换器的方式也应该有效，并且是一个错误，但它没有。我将打开一个问题来解决。