C# windows application key press event problem

if (e.KeyChar == (char)Keys.Enter)
{
//logic here

}

private void txtRollNumber_KeyPress(object sender, KeyPressEventArgs e)
{
 if (e.KeyChar == (char)Keys.Enter)
  {
  //Do your operation here
  }
}

myTextBox.KeyDown += (sender, eventArgs) => {
    //can optionally check eventArgs.Modifiers
    if (eventArgs.KeyCode == Keys.Enter)
        //...
};

#region just for fun :D
 
private string _lastKeys = "";
private readonly Dictionary<string,> _keyChecker = new Dictionary<string,>
	{
		// key code to press, msgbox header, msgbox text or
		// key code to press, switch to function execute, function to execute
		{"iddqd", new[] {"Cheater! :-)", "Godmode activated!"}},
		{"idkfa", new[] {"Cheater! :-)", "All Weapons unlocked!"}},
		{"aAa", new[] {"Testing", "Test!"}},
		{"aaa", new[] {"function", "close"}}
	};
 
private void KeyChecker(KeyEventArgs e)
{
	_lastKeys += e.Shift
		? ((char) e.KeyValue).ToString(CultureInfo.InvariantCulture)
		: ((char) e.KeyValue).ToString(CultureInfo.InvariantCulture).ToLower();

	foreach (var key in _keyChecker.Keys)
		if (_lastKeys.EndsWith(key))
		{
			if (_keyChecker[key][0] != "function")
				MessageBox.Show(_keyChecker[key][1], _keyChecker[key][0]);
			else
				KeyCheckerFunction(_keyChecker[key][1]);
			_lastKeys = "";
		}
 
	while (_lastKeys.Length > 100)
		_lastKeys = _lastKeys.Substring(1);
}
 
private void KeyCheckerFunction(string func)
{
	switch (func)
	{
		case "close":
			Close();
			break;
	}
}
 
#endregion just for fun :D

#region MAIN
private void FormMain_KeyDown(object sender, KeyEventArgs e)
{
	switch (e.KeyData)
	{
		case Keys.F1:
			MessageBox.Show("F1");
			break;
		case (Keys.F1 | Keys.Shift):
			MessageBox.Show("F1 + Shift");
			break;
		default:
			if (e.KeyCode >= Keys.A && e.KeyCode <= Keys.Z)
				KeyChecker(e);
			break;
	}
}
#endregion MAIN

private void newkey(object sender, KeyEventArgs e)
       {
           if (e.KeyCode  == Keys.Enter) textBox2.Focus();
       }

       private void textBox1_TextChanged(object sender, EventArgs e)
       {
           this.KeyDown += new System.Windows.Forms.KeyEventHandler(newkey);
           this.KeyPreview = true;
       }

private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
       {
           if (e.KeyChar == (char)Keys.Enter)
           {
               MessageBox.Show("Enter Pressed");
           }
       }