为什么UIButton没有回应接触？

Question

I've look at many responses and still cannot figure it out. I know the first line is a little weird, but its because it is inheriting from a super class that sets the headerview to search bar

searchBar = (UISearchBar *)self.tableView.tableHeaderView;
[[searchBar.subviews objectAtIndex:0] removeFromSuperview];

UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(0, -100, self.view.frame.size.width, 100)];
label.text = @"AAAA";
[searchBar addSubview:label];

UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
[button addTarget:self
           action:@selector(aMethod)
 forControlEvents:UIControlEventTouchDown];
[button setTitle:@"Show View" forState:UIControlStateNormal];
button.frame = CGRectMake(80.0, -60, 160.0, 40.0);

searchBar.exclusiveTouch = NO;
searchBar.userInteractionEnabled = NO;
label.userInteractionEnabled = NO;
button.userInteractionEnabled = YES;
[searchBar insertSubview:button atIndex:3];

Answer 1

userInteractionEnabled set to NO on a parent view will cascade down to all subviews. Thus, your instance of UIButton will appear unresponsive because the searchBar is disabled.

Answer 2

Here is your answer : searchBar.userInteractionEnabled = NO; If you are going to add a subview to a view that has userInteraction disabled then that subview won't receive touches. I haven't looked very good at your code to see if there are other mistakes.

Look at the frames in the first place :

button.frame = CGRectMake(80.0, -60, 160.0, 40.0);

UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(0, -100, self.view.frame.size.width, 100);

The button isn't visible at all , and the label the same , the objects are placed outside of bounds and that's why you cannot touch them.