C#

// assume this Click EventHandler is used by several buttons. I also assume you are going to want to execute different code for each different Button's Click Event.

private void ButtonsForWhatEver_Click(object sender, EventArgs e)
{
    switch((sender as Button).Name)
    {
        case "btn_whatEver1":
            // call a method with code common to all Buttons here
            // call code for this specific Button here
            break;
        case "btn_whatEver2":
            // call a method with code common to all Buttons here
            // call code for this specific Button here
            break;
        case "btn_whatEver4":
            // call a method with code common to all Buttons here
            // call code for this specific Button here
            break;
        default:
            // you reach here if you have not
            // had a match on a Button's name
            // ignore ? throw an error ? put up a Dialogue ?
            //
            // my choice would be to throw an error during development:
            // force yourself to correct a mis-call sooner rather than later
            break;
    }
}

Miwin Solutions wrote:

but I may have up to 250 buttons

case "button4":
case "button5":
  Console.WriteLine((sender as Button).Name);
  break;

private delegate void uniqueButtonCodeToExecute();

SomeButton.Tag = new uniqueButtonCodeToExecute(() => Console.WriteLine("in Button8's unique code"));

private void ButtonUniqueCode_Click(object sender, EventArgs e)
{
    ((sender as Button).Tag as uniqueButtonCodeToExecute)();
}

// using the same delegate shown above:
private Dictionary<object, uniqueButtonCodeToExecute> ButtonCodeDictionary = new Dictionary<object,uniqueButtonCodeToExecute>();

ButtonCodeDictionary.Add(SomeButton, () => Console.WriteLine("in Button8's unique code"));

private void ButtonsForWhatEver2_Click(object sender, EventArgs e)
{
    ButtonCodeDictionary[sender]();
}

ButtonCodeDictionary.Add(theButton, () => SomeUniqueButtonsMethod("Button8"));

private void SomeUniqueButtonsMethod(string buttonName)
{
   Console.WriteLine(buttonName);
}

eyesark wrote:

Please help!

bool isNew = true;
using (Mutex mutex = new Mutex(true, "yourAppName", out isNew))
{
    if (isNew)
    {
        Application.Run(new MainForm());
    }
}