BaseNumberConverter.cs

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using System.Globalization;
 
namespace System.ComponentModel;
 
public abstract class BaseNumberConverter : TypeConverter
{
    internal virtual bool AllowHex => true;
 
    internal abstract Type TargetType { get; }
 
    internal BaseNumberConverter()
    {
    }
 
    internal abstract object FromString(string value, int radix);
 
    internal abstract object FromString(string value, NumberFormatInfo formatInfo);
 
    internal abstract string ToString(object value, NumberFormatInfo formatInfo);
 
    public override bool CanConvertFrom(ITypeDescriptorContext? context, Type sourceType)
    {
        if (!(sourceType == typeof(string)))
        {
            return base.CanConvertFrom(context, sourceType);
        }
        return true;
    }
 
    public override object? ConvertFrom(ITypeDescriptorContext? context, CultureInfo? culture, object value)
    {
        if (value is string text)
        {
            string text2 = text.Trim();
            try
            {
                if (AllowHex && text2[0] == '#')
                {
                    return FromString(text2.Substring(1), 16);
                }
                if (AllowHex && (text2.StartsWith("0x", StringComparison.OrdinalIgnoreCase) || text2.StartsWith("&h", StringComparison.OrdinalIgnoreCase)))
                {
                    return FromString(text2.Substring(2), 16);
                }
                if (culture == null)
                {
                    culture = CultureInfo.CurrentCulture;
                }
                NumberFormatInfo formatInfo = (NumberFormatInfo)culture.GetFormat(typeof(NumberFormatInfo));
                return FromString(text2, formatInfo);
            }
            catch (Exception innerException)
            {
                throw new ArgumentException(System.SR.Format(System.SR.ConvertInvalidPrimitive, text2, TargetType.Name), "value", innerException);
            }
        }
        return base.ConvertFrom(context, culture, value);
    }
 
    public override object? ConvertTo(ITypeDescriptorContext? context, CultureInfo? culture, object? value, Type destinationType)
    {
        if (destinationType == null)
        {
            throw new ArgumentNullException("destinationType");
        }
        if (destinationType == typeof(string) && value != null && TargetType.IsInstanceOfType(value))
        {
            if (culture == null)
            {
                culture = CultureInfo.CurrentCulture;
            }
            NumberFormatInfo numberFormatInfo = (NumberFormatInfo)culture.GetFormat(typeof(NumberFormatInfo));
            return ToString(value, numberFormatInfo);
        }
        if (destinationType.IsPrimitive)
        {
            return Convert.ChangeType(value, destinationType, culture);
        }
        return base.ConvertTo(context, culture, value, destinationType);
    }
 
    public override bool CanConvertTo(ITypeDescriptorContext? context, Type? destinationType)
    {
        if (destinationType != null && destinationType.IsPrimitive)
        {
            return true;
        }
        return base.CanConvertTo(context, destinationType);
    }
}