Displaying stopwatch current time in TextBox in C#

Question

What I am looking for:

When my main form loads, I want 15 stopwatches created and 15 textbox.text's to be assigned to each stopwatch. These textboxes will display the current time of each timer after it is started:

       public void Form1_Load(object sender, EventArgs e)
    {
        StopWatchCreate();
    }

    public void StopWatchCreate()
    {
        Stopwatch stopwatch1 = new Stopwatch();
        TimerTextBox1.Text = stopwatch1.Elapsed.ToString("hh\\:mm\\:ss");
        Stopwatch stopwatch2 = new Stopwatch();
        TimerTextBox2.Text = stopwatch2.Elapsed.ToString("hh\\:mm\\:ss");
        Stopwatch stopwatch3 = new Stopwatch();
        TimerTextBox3.Text = stopwatch3.Elapsed.ToString("hh\\:mm\\:ss");
        Stopwatch stopwatch4 = new Stopwatch();
        TimerTextBox4.Text = stopwatch4.Elapsed.ToString("hh\\:mm\\:ss");
        Stopwatch stopwatch5 = new Stopwatch();
        TimerTextBox5.Text = stopwatch5.Elapsed.ToString("hh\\:mm\\:ss");
        Stopwatch stopwatch6 = new Stopwatch();
        TimerTextBox6.Text = stopwatch6.Elapsed.ToString("hh\\:mm\\:ss");
        Stopwatch stopwatch7 = new Stopwatch();
        TimerTextBox7.Text = stopwatch7.Elapsed.ToString("hh\\:mm\\:ss");
        Stopwatch stopwatch8 = new Stopwatch();
        TimerTextBox8.Text = stopwatch8.Elapsed.ToString("hh\\:mm\\:ss");
        Stopwatch stopwatch9 = new Stopwatch();
        TimerTextBox9.Text = stopwatch9.Elapsed.ToString("hh\\:mm\\:ss");
        Stopwatch stopwatch10 = new Stopwatch();
        TimerTextBox10.Text = stopwatch10.Elapsed.ToString("hh\\:mm\\:ss");
        Stopwatch stopwatch11 = new Stopwatch();
        TimerTextBox11.Text = stopwatch11.Elapsed.ToString("hh\\:mm\\:ss");
        Stopwatch stopwatch12 = new Stopwatch();
        TimerTextBox12.Text = stopwatch12.Elapsed.ToString("hh\\:mm\\:ss");
        Stopwatch stopwatch13 = new Stopwatch();
        TimerTextBox13.Text = stopwatch13.Elapsed.ToString("hh\\:mm\\:ss");
        Stopwatch stopwatch14 = new Stopwatch();
        TimerTextBox14.Text = stopwatch14.Elapsed.ToString("hh\\:mm\\:ss");
        Stopwatch stopwatch15 = new Stopwatch();
        TimerTextBox15.Text = stopwatch15.Elapsed.ToString("hh\\:mm\\:ss");
    }

After a button click I want the corresponding stopwatch to start and the textbox.text to display the current timer. The issue I am running into is under the button clock function:

public void button1_Click(object sender, EventArgs e)
    {
        Form1.stopwatch1.Start();
    }

but stopwatch1 is giving the error: 'TaskTracker.Form1' does not contain a definition for 'stopwatch1'

Thank you for your help with this!

The `stopwatch1` instance only live in `StopWatchCreate` scope what did you want to do? — D-Shih, Oct 31 '18 at 21:21
Have you tried putting it into the `public Form()` method instead of `Form1_Load()` ? — Jaskier, Oct 31 '18 at 21:24
You are creating the instances inside StopWatchCreate() and need to create at class level — Tito, Oct 31 '18 at 21:24
Possible duplicate of [C# local variable scope](https://stackoverflow.com/questions/12060748/c-sharp-local-variable-scope) — Ňɏssa Pøngjǣrdenlarp, Oct 31 '18 at 21:31

score 2 · Answer 1 · answered Oct 31 '18 at 21:37

Perhaps you seem to want this.

With a little modification in this code, you can create what you want.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace WindowsFormsApp23
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        Timer t1;

        Stopwatch s1;
        Stopwatch s2;


        private void Form1_Load(object sender, EventArgs e)
        {
            s1 = new Stopwatch();
            s2 = new Stopwatch();

            t1 = new Timer();
            t1.Interval = 1;
            t1.Tick += T1_Tick;
            t1.Start();
        }

        private void T1_Tick(object sender, EventArgs e)
        {
            textBox1.Text = s1.ElapsedMilliseconds.ToString();
            textBox2.Text = s2.ElapsedMilliseconds.ToString();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            s1.Start();
            s2.Start();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            s1.Stop();
            s2.Stop();
        }
    }
}

score 1 · Answer 2 · answered Oct 31 '18 at 21:37

First, as the comments says, all the Stopwatch variables must be fields of the Form, not local variables, as they are now.

Do like this:

public partial Form1: Form
{
      Stopwatch stopwatch1 = new Stopwatch();
      Stopwatch stopwatch2 = new Stopwatch();
      // etc

Then to display the current value of the StopWatches, you will need a Timer Component, simply drop a Timer on the Form.

Then write an eventhandler for the Timer, that looks like this:

private void Timer1_Tick(object sender, EventArgs e)
{
        TimerTextBox1.Text = stopwatch1.Elapsed.ToString("hh\\:mm\\:ss");
        TimerTextBox2.Text = stopwatch2.Elapsed.ToString("hh\\:mm\\:ss");
        // etc
}

The Timer should propably trigger once per second (set Interval to 1000).

Now the textboxes will show the value of the Stopwatches every second.

Displaying stopwatch current time in TextBox in C#

2 Answers2