public void RegisterClosed(Action handler)
{
if (wpf != null)
{
wpfClosed = (obj, args) =>
{
handler();
Dispose();
};
wpf.Closed += wpfClosed;
}
else if (winform != null)
{
winformClosed = (obj, args) =>
{
handler();
Dispose();
};
winform.FormClosed += winformClosed;
}
}