QueryPerformanceCounter,QueryPerformanceFrequency

 

        [DllImport("Kernel32.dll")]
        public static extern bool QueryPerformanceCounter(out long value);
        [DllImport("Kernel32.dll")]
        public static extern bool QueryPerformanceFrequency(out long value);
/*                 */////////////////////////////////////

        private void button1_Click_1(object sender, System.EventArgs e)
        ...{
            long counter_s = 0,counter_e = 0, freq = 0;
            QueryPerformanceCounter(out counter_s);
            QueryPerformanceCounter(out counter_e);

            QueryPerformanceFrequency(out freq);
            MessageBox.Show(string.Format("{0:.#######}",(counter_e - counter_s) / freq));

            MessageBox.Show(freq.ToString());

        }