Sample app showing DoubleBuffered property on DataGridView

DoubleBuffered

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Windows.Forms;

namespace DoubleBufferExample
{
    public partial class TestForm : Form
    {
        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new TestForm());
        }

        Stopwatch _stopwatch = new Stopwatch();
        Label _resultLabel;

        public TestForm()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            var dummyEntities = BuildEntities();

            _resultLabel = label1;
            _stopwatch.Restart();
            dataGridView1.DataSource = dummyEntities;
        }

        private void Grids_RowPostPaint(object sender, DataGridViewRowPostPaintEventArgs e)
        {
            if (e.RowIndex == 15)
            {
                _stopwatch.Stop();
                _resultLabel.Text = _stopwatch.ElapsedMilliseconds.ToString();
            }
        }

        private void button2_Click(object sender, EventArgs e)
        {
            var dummyEntities = BuildEntities();

            _resultLabel = label2;
            _stopwatch.Restart();
            dataGridView2.DataSource = dummyEntities;
        }

        private List<DummyEntity> BuildEntities()
        {
            var dummyEntities = new List<DummyEntity>();

            foreach (var i in Enumerable.Range(1, 16))
            {
                dummyEntities.Add(new DummyEntity { Id = i, Name = Path.GetRandomFileName() });
            }
            return dummyEntities;
        }

        private class DummyEntity
        {
            public int Id { get; set; }
            public string Name { get; set; }
        }
    }

    sealed class DoubleBufferedDataGridView : DataGridView
    {
        public DoubleBufferedDataGridView()
        {
            DoubleBuffered = true;
        }
    }
}