Sending message to child from parent

Question

I have class Child inherited from class Parent. What I want is to send message to child, which has implementation of that message. So it\'s like calling pure virtual function fr

Answer 1

Whether the method is present is checked at runtime. Therefore, even if the compiler warns you, the code could still succeed. But always check if self really defines that method first.

if ([self respondsToSelector:@selector(onCancel)]) {
  [self onCancel];
}

If you want to eliminate the warning, use -performSelector:.

if ([self respondsToSelector:@selector(onCancel)]) {
  [self performSelector:@selector(onCancel)];
}