回答

0

要獲得減,你可以創建負圖像的自定義按鈕,如果你看看可用的系統UIBar下面的蘋果文檔

...按鈕

http://developer.apple.com/library/ios/#documentation/uikit/reference/UIBarButtonItem_Class/Reference/Reference.html#//apple_ref/c/tdef/UIBarButtonSystemItem

沒有減可用的按鈕類型所以你必須自己創建。

使用下面的代碼來創建負圖像的按鈕,通過添加按鈕,自定義視圖創建UIBarButtonItem

UIImage *image=[UIImage imageNamed:@"minus.png"]; 
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom]; 
button.bounds = CGRectMake(0, 0, image.size.width, image.size.height);  
[button setImage:image forState:UIControlStateNormal]; 
[button addTarget:self action:@selector(Minus) forControlEvents:UIControlEventTouchUpInside];  
UIBarButtonItem *barButtonItem = [[UIBarButtonItem alloc] initWithCustomView:button]; 
self.navigationItem.rightBarButtonItem = barButtonItem; 
[barButtonItem release]; 
2

沒有,所有可用的圖標是here。您可以改爲使用自定義視圖。

0

我使用菜單編輯 - >表情符號&符號EM DASH符號。這就像一個負面但更寬。例如:

navigationItem.leftBarButtonItem = UIBarButtonItem(title: "—", style: .plain, target: self, action: #selector(removeColumn)) 

The EM DASH symbol