大家有没有遇到searchBar的取消按钮会出现特别小的情况，初次发现这种情况是在iOS10上，不过下边这种解决办法亲测不限系统

-(void)searchBarTextDidBeginEditing:(UISearchBar *)searchBar
{
    [searchBar setShowsCancelButton:YES animated:YES];
    for(id view in [searchBar.subviews[0] subviews])
    {
        if([view isKindOfClass:[UIButton class]])
        {
            UIButton *btn = (UIButton *)view;
            btn.titleLabel.font = [UIFont systemFontOfSize:16];
            [btn setContentEdgeInsets:UIEdgeInsetsMake(0, -5, 0, 0)];  //解决iOS10上按钮太小的问题
            btn.titleLabel.adjustsFontSizeToFitWidth = YES;
        }
    }
}