Here's how I did it:
public object GetParentByType(string TypeOfParent, object ChildObject)
{
string LocalTypeOfParent = "System.Windows.Controls." + TypeOfParent;
DependencyObject SearchChildObject = ChildObject as DependencyObject;
DependencyObject ComparingObject = VisualTreeHelper.GetParent(SearchChildObject) as DependencyObject;
if (ComparingObject == null)
ComparingObject = ((FrameworkElement)SearchChildObject).Parent as DependencyObject;
if (ComparingObject.GetType().ToString() != LocalTypeOfParent)
return GetParentByType(TypeOfParent, ComparingObject as object);
else
return ComparingObject as object;
}
And use it this way.
I have the Checked Event Handler on the CheckBox in the DataTemplate described on my initial question.
private void _SELECCIONADO_Checked(object sender, RoutedEventArgs e)
{
ComboBox OQueProcuro = (ComboBox)GetParentByType("ComboBox", sender);
}