PunkHPX8/PunkHPX8_MainPages/Converters/AllNoneCheckboxConverter.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Data;

namespace PunkHPX8_MainPages.Converters
{
   public class AllNoneCheckboxConverter : IMultiValueConverter
    {
        public object Convert(object[] values, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            bool result = (bool)values[0];
            for (int i = 0; i < values.Length; i++)
                if (result != (bool)values[i])
                    return null;

            return result;
        }

        public object[] ConvertBack(object value, Type[] targetTypes, object parameter, System.Globalization.CultureInfo culture)
        {
            object[] result = new object[targetTypes.Length];
            bool isChecked = (bool)value;

            for (int i = 0; i < result.Length; i++)
                if (isChecked)
                    result[i] = true;
                else
                    result[i] = false;

            return result;
        }
    }
}