Question

我的应用程序中有一个jquery事件日历，必须通过JSON输入提供。此时的输入看起来像这样：

[   
{ "date": "1352636408000", "type": "meeting", "title": "Poker Freak", "description": "Lorem Ipsum dolor set", "url": "http://www.event1.com/" },    
{ "date": "1351775676000", "type": "demo", "title": "Poker Freak", "description": "Lorem ipsum dolor sit amet, cveniris nisi ut aliquip ex ea commodo consequat.", "url": "http://www.event2.com/" },   
{ "date": "1351764876000", "type": "meeting", "title": "Poker Freak", "description": "Lorem Ipsum dolor set", "url": "http://www.event3.com/" } ]

它保存在JSON文件中，该文件是来自事件日历的演示文件。

另一方面，我有一个MSSQL表，用于控制事件表中的数据（Date as DateTime，Type as string等）。

我使用此命令获取数据：

        public static List<Event> GetAllEvents()
    {
        using (CyberDBDataContext db = new CyberDBDataContext())
        {
            return (from a in db.Events select a).ToList();
        }
    }

现在 - 如何将MSSQL Return查询（事件列表）转换为JSON？

Answer 1

您应该使用JSON.net库。这将是最简单的方法（在我看来，它是JSON最好的库之一）。

使用这些示例中的 ~~second~~ 第四格式

  string defaultJson = JsonConvert.SerializeObject(entry);
  // {"Details":"Application started.","LogDate":"\/Date(1234656000000)\/"}

  string javascriptJson = JsonConvert.SerializeObject(entry, new JavaScriptDateTimeConverter());
  // {"Details":"Application started.","LogDate":new Date(1234656000000)}

  string isoJson = JsonConvert.SerializeObject(entry, new IsoDateTimeConverter());
  // {"Details":"Application started.","LogDate":"2009-02-15T00:00:00Z"}

  string isoJson = JsonConvert.SerializeObject(entry, new TicksDateTimeConverter());
  // {"Details":"Application started.","LogDate":"1234656000000"}

使用自定义DateFormatter跟踪您的代码段：

public static string GetAllEvents()
{
    using (CyberDBDataContext db = new CyberDBDataContext())
    {
        return JsonConvert.SerializeObject((from a in db.Events select a).ToList(), new TicksDateTimeConverter());
    }
}

编辑： 以防您使用ASP.net MVC

Dunno如果它也适用于ASP.net MVC4之前的任何版本，但是因为版本4 JSON.net是默认的JSON序列化程序。所以你不需要再实施它了。

自定义转换器

我建议你实现如下的自定义转换器。基本上它与JavaScript转换器相同，但它应该只返回Ticks。

using System;
using System.Globalization;
using Newtonsoft.Json.Utilities;

namespace Newtonsoft.Json.Converters
{
  /// <summary>
  /// Converts a <see cref="DateTime"/> to and from a JavaScript date constructor (e.g. new Date(52231943)).
  /// </summary>
  public class TicksDateTimeConverter : DateTimeConverterBase
  {
    /// <summary>
    /// Writes the JSON representation of the object.
    /// </summary>
    /// <param name="writer">The <see cref="JsonWriter"/> to write to.</param>
    /// <param name="value">The value.</param>
    /// <param name="serializer">The calling serializer.</param>
    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
      long ticks;

      if (value is DateTime)
      {
        DateTime dateTime = (DateTime)value;
        DateTime utcDateTime = dateTime.ToUniversalTime();
        ticks = JsonConvert.ConvertDateTimeToJavaScriptTicks(utcDateTime);
      }
#if !PocketPC && !NET20
      else if (value is DateTimeOffset)
      {
        DateTimeOffset dateTimeOffset = (DateTimeOffset)value;
        DateTimeOffset utcDateTimeOffset = dateTimeOffset.ToUniversalTime();
        ticks = JsonConvert.ConvertDateTimeToJavaScriptTicks(utcDateTimeOffset.UtcDateTime);
      }
#endif
      else
      {
        throw new Exception("Expected date object value.");
      }

      writer.WriteValue(ticks);
    }

    /// <summary>
    /// Reads the JSON representation of the object.
    /// </summary>
    /// <param name="reader">The <see cref="JsonReader"/> to read from.</param>
    /// <param name="objectType">Type of the object.</param>
    /// <param name="existingValue">The existing property value of the JSON that is being converted.</param>
    /// <param name="serializer">The calling serializer.</param>
    /// <returns>The object value.</returns>
    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
      Type t = (ReflectionUtils.IsNullableType(objectType))
        ? Nullable.GetUnderlyingType(objectType)
        : objectType;

      if (reader.TokenType == JsonToken.Null)
      {
        if (!ReflectionUtils.IsNullableType(objectType))
          throw new Exception("Cannot convert null value to {0}.".FormatWith(CultureInfo.InvariantCulture, objectType));

        return null;
      }

      if (reader.TokenType != JsonToken.StartConstructor || !string.Equals(reader.Value.ToString(), "Date", StringComparison.Ordinal))
        throw new Exception("Unexpected token or value when parsing date. Token: {0}, Value: {1}".FormatWith(CultureInfo.InvariantCulture, reader.TokenType, reader.Value));

      reader.Read();

      if (reader.TokenType != JsonToken.Integer)
        throw new Exception("Unexpected token parsing date. Expected Integer, got {0}.".FormatWith(CultureInfo.InvariantCulture, reader.TokenType));

      long ticks = (long)reader.Value;

      DateTime d = JsonConvert.ConvertJavaScriptTicksToDateTime(ticks);

      reader.Read();

      if (reader.TokenType != JsonToken.EndConstructor)
        throw new Exception("Unexpected token parsing date. Expected EndConstructor, got {0}.".FormatWith(CultureInfo.InvariantCulture, reader.TokenType));

#if !PocketPC && !NET20
      if (t == typeof(DateTimeOffset))
        return new DateTimeOffset(d);
#endif

      return d;
    }
  }
}

数据库查询/自定义类到JSON？

1 个答案: