ios - 如何使 UIBarButtonItem 不可见但有效？

Question

我有这个返回 UIBarButtonItem 的方法，我想要不可见的按钮但是当有人点击它时工作，,,,,

- (UIBarButtonItem *)leftMenuBarButtonItem {

UIBarButtonItem *barbuttonitem = [[UIBarButtonItem alloc]
                                  initWithImage:[UIImage imageNamed:@"bacbbutton.png"] style:UIBarButtonItemStyleDone
                                  target:self
                                  action:@selector(leftSideMenuButtonPressed:)];


return barbuttonitem;
}

我怎样才能让这个按钮不可见，但是只要点击那个角落或导航栏，按钮就会起作用，但可见性应该是隐藏的......

Answer 1

UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];
[btn setImage:[UIImage imageNamed:@"bacbbutton.png"] forState:UIControlStateNormal];
[btn addTarget:self action:@selector(leftSideMenuButtonPressed:) forControlEvents:UIControlEventTouchUpInside];
btn.alpha = 0.3;
UIBarButtonItem *bar = [[UIBarButtonItem alloc] initWithCustomView:btn];