public static frmEmissores GetChild(mdiPrincipal parent = null)
{
if (_childInstance == null)
{
_childInstance = new frmEmissores();
_childInstance.MdiParent = parent;
}
return(_childInstance);
}
private void btnEmissores_Click(object sender, EventArgs e)
{
frmEmissores frm = frmEmissores.GetChild(this);
frm.Show();
}