UIButton shadow color and shadow are not displayed

Question

shadow doesn't work why? I write UiBarbuttonItem like, ex:

UIImage *imageNomal = [UIImage imageNamed:@"Back_A"]; UIImage *imageHight = [UIImage imageNamed:@"Back_B"]; UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom]; button.bounds = CGRectMake(0, 0, imageNomal.size.width, imageNomal.size.height+2); [button.layer setShadowColor:[[UIColor whiteColor] CGColor]]; [button.layer setShadowOffset:CGSizeMake(0, 2)]; [button setImage:imageNomal forState:UIControlStateNormal]; [button setImage:imageHight forState:UIControlStateHighlighted]; [button addTarget:nav action:@selector(backClick:) forControlEvents:UIControlEventTouchUpInside]; __autoreleasing UIBarButtonItem *barButtonItem = [[UIBarButtonItem alloc] initWithCustomView:button]; 

Answer 1

You need to set shadowOpacity to something greater than 0.