form.cs

using System;
using System.Collections.Generic;
using System.Diagnostics;
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.Shapes;

namespace tosproxy
{
    /// <summary>
    /// Interaction logic for ProcessChooser.xaml
    /// </summary>
    public partial class ProcessChooser : Window
    {
        public List<Process> ProcessList {get; private set;}

        public ProcessChooser()
        {
            GetProcessList();
            this.DataContext = this;
            InitializeComponent();
        }

        private void GetProcessList()
        {
            ProcessList = Process.GetProcesses().ToList();

            Trace.WriteLine("PROCESS LIST:\n");
            Trace.WriteLine(ProcessList.First().Id);
        }
    }
}

form.xaml

<Window x:Class="tosproxy.ProcessChooser"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        mc:Ignorable="d"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:tosproxy"
        xmlns:diagnostics="clr-namespace:System.Diagnostics;assembly=System"
        Title="ProcessChooser" Height="300" Width="300">
    <Grid>
        
        <DataGrid x:Name="ProcessListView" VerticalAlignment="Top" ItemsSource="{Binding ProcessList}"
                  AutoGenerateColumns="False" CanUserResizeColumns="True">
            <DataGrid.Columns>
                <DataGridTextColumn Width="40" Header="PID" Binding="{Binding Id}" />
                <DataGridTextColumn Width="*" Header="Name" Binding="{Binding ProcessName}" />
            </DataGrid.Columns>
            
        </DataGrid>
        
    </Grid>
</Window>