... 그냥 Start() & Stop() ... 끝... -_-
using System.Diagnostics;
private void btnChangColor02_Click(object sender, EventArgs e)
{
Stopwatch sw = new Stopwatch();
sw.Start();
// 처리할 로직...
sw.Stop();
MessageBox.Show(sw.ElapsedMilliseconds.ToString() + "ms");
}