C#

private void findAndReplaceToolStripMenuItem_Click(object sender, EventArgs e)
{
    frmFindReplace find = new frmFindReplace();
    find.Clicked += new ButtonClick(find_Clicked);
    find.ShowDialog();
}

// TextEventArgs.cs
using System;

public class TextEventArgs : EventArgs
{
    private string text;

    public TextEventArgs(string text)
    {
        this.text = text;
    }

    public string Text
    {
        get { return text; }
    }
}

// FormFindAndReplace.cs
using System;
using System.Windows.Forms;

public partial class FormFindAndReplace : Form
{
    public event EventHandler<TextEventArgs> FindClicked;

    public FormFindAndReplace()
    {
        InitializeComponent();
    }

    private void buttonFind_Click(object sender, EventArgs e)
    {
        OnFindClicked(new TextEventArgs(textBox.Text));
    }

    protected virtual void OnFindClicked(TextEventArgs e)
    {
        EventHandler<TextEventArgs> eh = FindClicked;
        if (eh != null)
            eh(this, e);
    }
}

// FormMain.cs
using System;
using System.Windows.Forms;

public partial class FormMain : Form
{
    private FormFindAndReplace formFindAndReplace = null;

    public FormMain()
    {
        InitializeComponent();
    }

    private void findAndReplaceToolStripMenuItem_Click(object sender, EventArgs e)
    {
        if (formFindAndReplace == null)
            formFindAndReplace = new FormFindAndReplace();
        formFindAndReplace.FindClicked += formFindAndReplace_FindClicked;
        formFindAndReplace.FormClosing += formFindAndReplace_FormClosing;
        formFindAndReplace.Show();
    }

    private void formFindAndReplace_FindClicked(object sender, TextEventArgs e)
    {
        // Do your thing with e.Text
        Console.WriteLine(e.Text);
    }
    private void formFindAndReplace_FormClosing(object sender, FormClosingEventArgs e)
    {
        formFindAndReplace.FormClosing -= formFindAndReplace_FormClosing;
        formFindAndReplace.FindClicked -= formFindAndReplace_FindClicked;
        formFindAndReplace = null;
    }
}

PIEBALDconsult wrote:

The Singleton pattern is more for C++ and is not of much use in C#

private void dataGridView1_MouseDown(object sender, MouseEventArgs e)
       {
           try
           {

               if (e.Button == MouseButtons.Right)
               {
                   DataGridView.HitTestInfo hit = dataGridView1.HitTest(e.X, e.Y);
                   dataGridView1.CurrentCell = dataGridView1[0, hit.RowIndex];
               }
           }
           catch
           {
           }
       }

private void doSomething()
{
   DialogResult theResult = MessageBox.Show("Is this working?", "Well.......",MessageBoxButtons.YesNo,MessageBoxIcon.Question);

   if (theResult == DialogResult.Yes)
   {
   //Go and do something here
   }
}

if (MessageBox.Show("Is this working?", "Well.......", MessageBoxButtons.YesNo, MessageBoxIcon.Question) == DialogResult.Yes)
{
}
else // no
{
}

MessageBoxButton buttons = MessageBoxButton.OKCancel;
  MessageBoxImage icon = MessageBoxImage.Information;
  MessageBoxResult defaultResult = MessageBoxResult.OK;
  // Show message box
  MessageBoxResult result = MessageBox.Show(message, caption, buttons, icon, defaultResult);