为什么JavaScriptSerializer会忽略我的转换器?

时间:2010-06-23 17:37:46

标签: c# json serialization javascriptserializer

我正在尝试以无法由.NET的DateTime结构直接解析的格式读取包含日期/时间的JSON对象。为了避免在我的结构中有一个'int'字段的日期/时间,我写了一个自定义DateTimeConverter:

public class DateTimeConverter : JavaScriptConverter {
  public override IEnumerable<Type> SupportedTypes {
    get { return new Type[] { typeof(DateTime), typeof(DateTime?) }; }
  }

  public override IDictionary<string, object> Serialize(
    object obj, JavaScriptSerializer serializer
  ) { throw new NotImplementedException(); }

  public override object Deserialize(
    IDictionary<string, object> dictionary, Type type,
    JavaScriptSerializer serializer
  ) {
    return DateTime.Now;
  }
}

但是当我用JavaScriptSerializer读取JSON字符串时,它不使用我的自定义转换器:

public struct TextAndDate {
  public string Text;
  public DateTime Date;
}

static void Main() {
  string json =
    "{" +
    "  \"text\": \"hello\", " +
    "  \"date\": \"1276692024\"" +
    "}";

  var serializer = new JavaScriptSerializer();
  serializer.RegisterConverters(new [] { new DateTimeConverter() });
  var test = serializer.Deserialize<TextAndDate>(json);
}

直接反序列化DateTime值时使用转换器 ,而不是在反序列化包含DateTime值的类型时。

为什么呢? 没有编写自定义DateTime类型或使用int?

的任何方法

1 个答案:

答案 0 :(得分:0)

您应该在DateTimeConverter班级进行细微更改:

public class DateTimeConverter : JavaScriptConverter {
    public override IEnumerable<Type> SupportedTypes {
        get { return new Type[] { typeof (TextAndDate) }; }
    }

    public override IDictionary<string, object> Serialize (
        object obj, JavaScriptSerializer serializer
    ) { throw new NotImplementedException (); }

    public override object Deserialize (
        IDictionary<string, object> dictionary, Type type,
        JavaScriptSerializer serializer
    ) {
        if (type == typeof (TextAndDate)) {
            TextAndDate td = new TextAndDate ();
            if (dictionary.ContainsKey ("text"))
                td.Text = serializer.ConvertToType<string> (
                                            dictionary["text"]);
            //if (dictionary.ContainsKey ("date"))
                td.Date = DateTime.Now;
            return td;
        }
        else
            return null;
    }
}
根据评论

更新:在我看来,您应该使用Message Inspectors技术(请参阅http://msdn.microsoft.com/en-us/library/aa717047.aspx)。请查看How to ignore timezone of DateTime in .NET WCF client?以获取示例。