Code

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace WiskundigeBewerkingenGetransponeerde
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        int[,] GetallenGrid = new int[4, 4] { { 1, 2, 3, 4 }, { 5, 6, 7, 8 }, { 9, 10, 11, 12 }, { 13, 14, 15, 16 } };
        int column, row;
        private void btnSend(object sender, RoutedEventArgs e)
        {
            for (int i = 0; i <= 3; i++)
            {

                for (int ix = 0; ix < 4; ix++)
                {
                    column +=1;
                }
                row += 1;
            }

            MessageBox.Show(column +  " kolom"  +  row + " rij".ToString());
        }
    }
}