回答

0

要获得减,你可以创建负图像的自定义按钮,如果你看看可用的系统UIBar下面的苹果文档

...按钮

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

没有减可用的按钮类型所以你必须自己创建。

使用下面的代码来创建负图像的按钮,通过添加按钮,自定义视图创建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

没有,所有可用的图标是here。您可以改为使用自定义视图。

0

我使用菜单编辑 - >表情符号&符号EM DASH符号。这就像一个负面但更宽。例如:

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

The EM DASH symbol