kev/Drawer/AI/Converters/FormNullableDoubleConverter.cs

using System;
using System.Globalization;
using Avalonia.Data.Converters;

namespace AI.Converters
{
    /// <summary>
    /// 将 double? 转为 double，用于 NumericUpDown 的 Minimum/Maximum（null 时用默认边界）
    /// ConverterParameter: "min" -> null 转为 double.MinValue, "max" -> null 转为 double.MaxValue
    /// </summary>
    public class FormNullableDoubleConverter : IValueConverter
    {
        public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
        {
            if (value is double d)
            {
                return d;
            }

            if (value is decimal dec)
            {
                return (double)dec;
            }
            var key = parameter?.ToString()?.ToLowerInvariant();
            return key == "max" ? double.MaxValue
                : key == "step" ? 1d
                : double.MinValue;
        }

        public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
            => throw new NotImplementedException();
    }
}