Aws-sdk-net: DateTime 不支持与 DocumentModel 的往返序列化

DocumentModel Primitive 不正确支持往返序列化。 它应该在序列化 DateTime 时使用格式说明符“o”，以确保正确保留时区和毫秒。

我在下面创建了一个 IPropertyConverter 来说明 DateTime 和 NullableDateTime 的正确序列化。

using Amazon.DynamoDBv2.DataModel;
using Amazon.DynamoDBv2.DocumentModel;
using System.Globalization;

/// <summary>
/// The <see cref="IPropertyConverter"/> to properly support round-trip serialization of <see cref="DateTime"/>.
/// </summary>
public class RoundTripNullableDateTimeTypeConverter : IPropertyConverter
{
    /// <summary>
    /// Converts the <c>value</c> to a <see cref="Primitive"/>.
    /// </summary>
    /// <param name="value">The value to convert.</param>
    /// <returns>The primitive of the <c>value</c>.</returns>
    public DynamoDBEntry ToEntry(object value)
    {
        var date = value as DateTime?;
        return new Primitive 
        {
            Value = date.HasValue ? date.Value.ToString("o", CultureInfo.InvariantCulture) : null
        };
    }

    /// <summary>
    /// Converts the <c>entry</c> to <see cref="DateTime"/>.
    /// </summary>
    /// <param name="entry">The entry to convert.</param>
    /// <returns>The date time of the entry.</returns>
    public object FromEntry(DynamoDBEntry entry)
    {
        var entryString = entry.AsString();
        if (string.IsNullOrEmpty(entryString))
            return null;
        else
            return DateTime.ParseExact(entryString, "o", CultureInfo.InvariantCulture, DateTimeStyles.RoundtripKind);
    }
}

/// <summary>
/// The <see cref="IPropertyConverter"/> to properly support round-trip serialization of <see cref="DateTime"/>.
/// </summary>
public class RoundTripDateTimeTypeConverter : IPropertyConverter
{
    /// <summary>
    /// Converts the <c>value</c> to a <see cref="Primitive"/>.
    /// </summary>
    /// <param name="value">The value to convert.</param>
    /// <returns>The primitive of the <c>value</c>.</returns>
    public DynamoDBEntry ToEntry(object value)
    {
        return new Primitive
        {
            Value = ((DateTime)value).ToString("o", CultureInfo.InvariantCulture)
        };
    }

    /// <summary>
    /// Converts the <c>entry</c> to <see cref="DateTime"/>.
    /// </summary>
    /// <param name="entry">The entry to convert.</param>
    /// <returns>The date time of the entry.</returns>
    public object FromEntry(DynamoDBEntry entry)
    {
        return DateTime.ParseExact(entry.AsString(), "o", CultureInfo.InvariantCulture, DateTimeStyles.RoundtripKind);
    }
}

一些重要的参考资料：

• 标准日期和时间格式字符串
• DateTime 是否相对于 ToUniversalTime 和 ToLocalTime 往返？