private void listViewFolders_KeyDown(object sender, KeyEventArgs e)
{
switch (e.KeyCode)
{
case Keys.Delete:
menuItemDelete_Click (sender, null);
break;
case Keys.Insert:
menuItemAddFolder_Click (sender, null);
break;
case Keys.Enter:
listViewFolders_DoubleClick (sender, null);
break;
}
}