iPhone开发技巧之私有API（4）— UIBarButtonItem

如上所示，UIBarButtonSystemItem 的 100 ～ 110 就是系统提供的一些未公开的标准icon。

 NSMutableArray *items = [NSMutableArray array];
UIBarButtonItem *item = nil;
for (int i = 100; i <= 109; i++) {
    item = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:i target:nil action:nil];
    item.style = UIBarButtonItemStyleBordered;
    [items addObject:item];
    [item release];
}
item = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:110 target:nil action:nil];
item.style = UIBarButtonItemStylePlain;
[items addObject:item];
[item release];
toolbar.items = items;