我需要在导航栏中隐藏右键,然后在用户 Select 一些选项后取消隐藏.
不幸的是,以下方法不起作用:
NO GOOD: self.navigationItem.rightBarButtonItem.hidden = YES; // FOO CODE
有办法吗?
我需要在导航栏中隐藏右键,然后在用户 Select 一些选项后取消隐藏.
不幸的是,以下方法不起作用:
NO GOOD: self.navigationItem.rightBarButtonItem.hidden = YES; // FOO CODE
有办法吗?
通过将引用设置为nil来隐藏该按钮,但是如果以后要恢复该按钮,则需要保留该按钮的副本,以便重新分配该按钮.
UIBarButtonItem *oldButton = self.navigationItem.rightBarButtonItem;
[oldButton retain];
self.navigationItem.rightBarButtonItem = nil;
//... later
self.navigationItem.rightBarButtonItem = oldButton;
[oldButton release];
就我个人而言,在我的应用程序中,我把导航按钮变成@properties,这样我就可以扔掉&;随意重新创建它们,比如:
//mycontroller.h
UIBarButtonItem *rightNavButton;
@property (nonatomic, retain) UIBarButtonItem *rightNavButton;
//mycontroller.m
@synthesize rightNavButton;
- (UIBarButtonItem *)rightNavButton {
if (!rightNavButton) {
rightNavButton = [[UIBarButtonItem alloc] init];
//configure the button here
}
return rightNavButton;
}
//later, in your code to show/hide the button:
self.navigationItem.rightBarButtonItem = self.rightNavButton;