Object A is the parent object and object B is child object. object B has new button override with VF page. when I am clicking the new button of obj B from related list A I need Obj A's Id. For this I have added following lines in controller
String str = System.currentPageReference().getParameters().get('retURL').substring(1,16); Id myId = (Id)str;
This works for classic view for lightning view am getting Error like
Invalid id: lightning/cb/re An unexpected error has occurred. Your development organization has been notified.
Anyone knows about how to solve this?