C#

Quote:

If there is some kind of error, then the main form will show a modal error MessageBox, which has the main form as its parent.

using System;
using System.Windows.Forms;

namespace YourNameSpace
{
    public partial class SecondaryForm : Form
    {
        public SecondaryForm()
        {
            InitializeComponent();
        }

        public Action<string, string, DateTime> SendErrorMessage;

        // create an error
        private void button1_Click(object sender, EventArgs e)
        {
            try
            {
                throw new ArgumentException("some error");

            }
            catch (Exception ex)
            {
                SendErrorMessage?.Invoke(ex.Message, ex.Source, DateTime.Now);
            }
        }
    }
}

using System;
using System.ComponentModel;
using System.Windows.Forms;

namespace YourNameSpace
{
    public partial class MainForm : Form
    {
        public MainForm()
        {
            InitializeComponent();
        }

        private SecondaryForm secondaryForm = new SecondaryForm();
        private ErrorReportForm errForm = new ErrorReportForm();

        private void Form1_Load(object sender, EventArgs e)
        {
            errForm.Owner = this;
            secondaryForm.SendErrorMessage = SendErrorMessage;
            errForm.Closing += errFormOnClosing;
        }

        private void button1_Click(object sender, EventArgs e)
        {
            secondaryForm?.Show();
        }

        private void SendErrorMessage(string err, string src, DateTime dtime)
        {
            this.BringToFront();
            errForm.ShowErrForm(err, src, dtime);
        }

        private void errFormOnClosing(object sender, CancelEventArgs e)
        {
            secondaryForm.BringToFront();
        }
    }
}

using System;
using System.Windows.Forms;

namespace YourNameSpace
{
    public partial class ErrorReportForm : Form
    {
        public ErrorReportForm()
        {
            InitializeComponent();
        }

        public void ShowErrForm(string err = "", string src = "", DateTime dt = default(DateTime))
        {
            tbxErr.Text = err;
            tbxSrc.Text = src;

            tbxDate.Text = dt.ToLongDateString();
            tbxTime.Text = dt.ToLongTimeString();

            this.Show();
        }
    }
}