private static object Attach(
FrameworkElement element,
Func <object> viewModelFactory,
ref bool attached,
ref bool attaching,
out IViewModel attachment)
{
Contract.Requires(element != null);
Contract.Requires(viewModelFactory != null);
Contract.Requires(!attached);
Contract.Ensures(Contract.ValueAtReturn(out attached));
object viewModel;
attaching = true;
try
{
viewModel = viewModelFactory();
element.DataContext = viewModel;
attachment = viewModel as IViewModel;
if (attachment != null)
{
if (attachment.IsAttached)
{
attachment.Detach();
}
attachment.Attach(element);
}
}
finally
{
attaching = false;
}
attached = true;
return(viewModel);
}