Question

I have a variable: string currentTime in the constructor:

currentTime = DateTime.Now.ToString("HH:mm:ss tt");

And in the event Form1_FormClosing i have:

currentTimeClosed = DateTime.Now.ToString("HH:mm:ss tt");

Now i want to calculate the diffrenece between the two strings times and get the time the user used something like currenttimeClosed - currentTime = 10 minutes and 10 seconds
So i know the user used the program 10 minutes and 10 seconds.

How can i do it ?

Answer 1

First off, you don’t need to store strings – just store the DateTime directly.

You can subtract the two to get a TimeSpan telling you the difference and output the value of that.

// fields
DateTime currentTime;
DateTime currentTimeClosed;

// Somewhere in constructor
currentTime = DateTime.Now;

// in Form1_FormClosing
currentTimeClosed = DateTime.Now;

var difference = currentTimeClosed  - currentTime;

Console.Write(string.Format("{0} minutes and {1} seconds", 
                            (int)difference.TotalMinutes, 
                            difference.Seconds));