TransparentIfNull.cs

using System.Globalization;
using NeuroAccessMaui.UI.Pages.Main.Settings;
 
namespace NeuroAccessMaui.UI.Converters
{
    public class TransparentIfNull : IValueConverter, IMarkupExtension
    {
        public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
        {
            if (value is null)
                return Colors.Transparent;
 
            try
            {
                string Key = SettingsViewModel.CurrentDisplayMode == AppTheme.Light ? "InputFieldsContentPrimaryLight" : "InputFieldsContentPrimaryDark";
                if (!(App.Current?.Resources.TryGetValue(Key, out object Obj) ?? false))
                    return Colors.Transparent;
 
                if (Obj is Color Color)
                    return Color;
                else
                    return Colors.Transparent;
            }
            catch (Exception)
            {
                return Colors.Transparent;
            }
        }
 
        public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
        {
            return value;
        }
 
        public object ProvideValue(IServiceProvider serviceProvider)
        {
            return this;
        }
    }
}