如何向UINavigationController添加右键？ [英] How to add a right button to a UINavigationController?

问题描述

我正在尝试将一个刷新按钮添加到导航控制器的顶部栏但没有成功。

I am trying to add a refresh button to the top bar of a navigation controller with no success.

这是标题：

@interface PropertyViewController : UINavigationController {

}

以下是我尝试添加它的方法：

Here is how I am trying to add it:

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
    if (self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]) {
        UIBarButtonItem *anotherButton = [[UIBarButtonItem alloc] initWithTitle:@"Show" style:UIBarButtonItemStylePlain
                                          target:self action:@selector(refreshPropertyList:)];      
        self.navigationItem.rightBarButtonItem = anotherButton;
    }
    return self;
}

推荐答案

尝试在viewDidLoad中执行此操作。一般来说，你应该推迟任何事情直到那一点，当UIViewController被引入时，它仍然可能在它显示之前很长一段时间，没有必要提前做好工作并且占用内存。

Try doing it in viewDidLoad. Generally you should defer anything you can until that point anyway, when a UIViewController is inited it still might be quite a while before it displays, no point in doing work early and tying up memory.

- (void)viewDidLoad {
  [super viewDidLoad];

  UIBarButtonItem *anotherButton = [[UIBarButtonItem alloc] initWithTitle:@"Show" style:UIBarButtonItemStylePlain target:self action:@selector(refreshPropertyList:)];          
  self.navigationItem.rightBarButtonItem = anotherButton;
  // exclude the following in ARC projects...
  [anotherButton release];
}

至于为什么它目前不工作，我不能说在没有看到更多代码的情况下100％确定，但是在init和视图加载之间发生了很多事情，并且您可能正在做一些导致navigationItem在其间重置的事情。

As to why it isn't working currently, I can't say with 100% certainty without seeing more code, but a lot of stuff happens between init and the view loading, and you may be doing something that causes the navigationItem to reset in between.

这篇关于如何向UINavigationController添加右键？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！