酒吧按鈕不顯示

Question

我想使用自定義barbutton，將有一些圖像。 我正在做如下code.but barbutton不顯示。

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; 

Answer 1

，你必須爲你添加到BarButton

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

按鈕框架

Answer 2

你必須給圖像的狀態選擇和正常。那麼它會出現在你身上。這只是一個提示。但嘗試一下。

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

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

nowPlaying = [[UIBarButtonItem alloc] initWithCustomView:button]; 
self.navigationItem.rightBarButtonItem = nowPlaying;