Classes exercise Stopwatch: try/catch block

C#
1

I’m working on the Ultimate C# series part II. I have most of the exercise done with working code. However, I cannot figure out how to implement a try/catch block that throws InvalidOperationException when the StartMethod() is run twice. Can anyone help with this ? This is my Stopwatch class:

using System;

namespace stopwatch
{
public class Stopwatch
{
public DateTime Start { get; private set; }

    public DateTime Stop { get; private set; }

    public DateTime StartMethod()
    {
        return Start = DateTime.Now;
    }

    public DateTime StopMethod()
    {
        return Stop = DateTime.Now;
    }


}

}

3

Much simpler than it seemed in the end:

throw new InvalidOperationException(“Stopwatch is already running”);