ios - How do I access a button in a subview -

i want implement fade in/out in horizontal scroll have, can't figure out how access button in subview of uiscrollview. i'm trying implement fade in/out stackoverflow.

this code...

        game *game = (game *)[_schedule.games objectatindex:i];         uibutton *button = [[uibutton alloc] initwithframe:cgrectmake(x, 20, 150, 100)];         [button setbackgroundimage:[uiimage imagenamed:game.opponent] forstate:uicontrolstatenormal];         //[button settitle:game.opponent forstate:uicontrolstatenormal];         [_gamescrolllist addsubview:button]; 

how can add observer button, can done?

        [self.scrollview addobserver:[self.contentviews objectatindex:i]                            forkeypath:@"contentoffset"                               options:nskeyvalueobservingoptionnew                              context:@selector(updatealpha:)]; 

to access reference of button added subview, can:

• use button ivar, saving reference use later;

• similarly, use button property;

• iterate through subviews of _gamescrolllist, looking subview of uibutton's class (not recommended, work if has 1 uibutton subview)

example of how implement second approach. declare property:

@property(nonatomic, strong) uibutton *button; 

and then:

    game *game = (game *)[_schedule.games objectatindex:i];     self.button = [[uibutton alloc] initwithframe:cgrectmake(x, 20, 150, 100)];     [self.button setbackgroundimage:[uiimage imagenamed:game.opponent] forstate:uicontrolstatenormal];     //[self.button settitle:game.opponent forstate:uicontrolstatenormal];     [_gamescrolllist addsubview:self.button]; 

so, after, when want access button somewhere, call property

self.button.alpha = 0.5; //example of interation button 

if not looking for, should edit question more clear.

hope helped.