Simple Stopwatch Class

[jmcilhinney]

Just for the hell of it. Not tested extensively.

    class Stopwatch
    {
        private DateTime m_StartTime;   // The time the stopwatch was last started.
        private TimeSpan m_Elapsed;     // The amount of elapsed time.
        private bool m_Running;         // Whether the stopwatch is currently running.

        /// <summary>
        /// The amount of elapsed time.
        /// </summary>
        public TimeSpan Elapsed
        {
            get
            {
                TimeSpan elapsed = this.m_Elapsed;

                if (this.m_Running)
                {
                    elapsed = elapsed.Add(DateTime.Now.Subtract(this.m_StartTime));
                }

                return elapsed;
            }
            set { this.m_Elapsed = value; }
        }

        /// <summary>
        /// The current state of the stopwatch.
        /// </summary>
        public bool Running
        {
            get { return m_Running; }
            set { m_Running = value; }
        }	
	
        public Stopwatch()
        {
            // Initialise with no time elapsed.
            this.m_Elapsed = TimeSpan.Zero;
            this.m_Running = false;
        }

        /// <summary>
        /// Start the stopwatch running.
        /// </summary>
        /// <returns>
        /// True if the stopwatch was started; false if the stopwatch was already running.
        /// </returns>
        public bool Start()
        {
            bool result;

            if (this.m_Running)
            {
                // The stopwatch is already running.
                result = false;
            }
            else
            {
                this.m_StartTime = DateTime.Now;
                this.m_Running = true;
                result = true;
            }

            return result;
        }

        /// <summary>
        /// Stop the stopwatch running
        /// </summary>
        /// <returns>
        /// True if the stopwatch was stopped; false if the stopwatch was not running.
        /// </returns>
        public bool Stop()
        {
            bool result;

            if (this.m_Running)
            {
                this.m_Elapsed = this.m_Elapsed.Add(DateTime.Now.Subtract(this.m_StartTime));
                this.m_Running = false;
                result = true;
            }
            else
            {
                // The stopwatch is not running.
                result = false;
            }

            return result;
        }

        /// <summary>
        /// Resets the elapsed time to zero.
        /// </summary>
        public void Clear()
        {
            // Set the start time to now in case the stopwatch is running.
            this.m_StartTime = DateTime.Now;
            this.m_Elapsed = TimeSpan.Zero;
        }
    }

[jmcilhinney]

Removed the line from the Start method that reset the elapsed time. That line had been left in in error.