DiscordChatExporter/DiscordChatExporter.Gui/Converters/DateTimeOffsetToDateTimeConverter.cs

using System;
using System.Globalization;
using System.Windows.Data;

namespace DiscordChatExporter.Gui.Converters;

[ValueConversion(typeof(DateTimeOffset?), typeof(DateTime?))]
public class DateTimeOffsetToDateTimeConverter : IValueConverter
{
    public static DateTimeOffsetToDateTimeConverter Instance { get; } = new();

    public object? Convert(object value, Type targetType, object parameter, CultureInfo culture) => 
        value is DateTimeOffset dateTimeOffsetValue
            ? dateTimeOffsetValue.DateTime 
            : default(DateTime?);

    public object? ConvertBack(object value, Type targetType, object parameter, CultureInfo culture) => 
        value is DateTime dateTimeValue 
            ? new DateTimeOffset(dateTimeValue)
            : default(DateTimeOffset?);
}