ios - 条形按钮不显示

我想使用具有一些图像的自定义barbutton。
我正在做下面的代码。但是barbutton没有显示。

 UIButton * button = [UIButton buttonWithType:UIButtonTypeCustom];
[button setImage:[UIImage imageNamed:@"icon.png"] forState:UIControlStateNormal];

[button addTarget:self action:@selector(nowPlayingButtonClicked) forControlEvents:UIControlEventTouchUpInside];

nowPlaying = [[UIBarButtonItem alloc] initWithCustomView:button];
nowPlaying.action = @selector(nowPlayingButtonClicked);
nowPlaying.target = self;

self.navigationItem.rightBarButtonItem = nowPlaying;

最佳答案

您必须为添加到BarButton的Button设置框架

   button.frame = CGRectMake(0, 0, 50, 30);