ios 如何禁用 UIBarButtonItem？

How to disable UIBarButtonItem?

提问by Dan Loewenherz

I have a UIBarButtonItem that just doesn't want to get disabled. Short version: when I call

我有一个不想被禁用的 UIBarButtonItem。简短版本：当我打电话时

[myBarButtonItem setEnabled:NO];

Nothing happens.

没发生什么事。

myBarButtonItemis an IBOutlet in myVIewController. myViewControllerhas been added as an object to MainWindowin Interface Builder. The myBarButtonItemoutlet has been connected to the BarButtonItem, and has the corresponding @syntesizeand propertylines set.

myBarButtonItem是 中的 IBOutlet myVIewController。myViewController已作为对象添加到MainWindowInterface Builder 中。该myBarButtonItem出口被连接到所述BarButtonItem，并具有相应的@syntesize和property线集。

@property (nonatomic, retain) IBOutlet UIBarButtonItem *myBarButtonItem;

In myViewController.m,

在 myViewController.m 中，

@synthesize myBarButtonItem;

Anyone have an idea why the above setEnabledmethod has no affect? Thanks!

任何人都知道为什么上述setEnabled方法没有影响？谢谢！

UPDATE: Fixed it! Don't know why, but apparently the outlet wasn't being set. I used my App Delegate as the parent object for the UIBarButtonItem, and all worked out.

更新：修复它！不知道为什么，但显然没有设置出口。我使用我的 App Delegate 作为 UIBarButtonItem 的父对象，一切都解决了。

回答by Nicu Surdu

You can disable the left navigation button from inside an UIViewController like this, without using any IBOutlet:

您可以像这样从 UIViewController 内部禁用左侧导航按钮，而无需使用任何 IBOutlet：

self.navigationItem.leftBarButtonItem.enabled = NO;

To disable the right navigation button:

要禁用右侧导航按钮：

self.navigationItem.rightBarButtonItem.enabled = NO;

Swift3

斯威夫特3

self.navigationItem.rightBarButtonItem?.isEnabled = false

回答by hotpaw2

If your toolbar has an IBOutlet (and you've checked to make sure it's non-nil), try:

如果您的工具栏有一个 IBOutlet（并且您已检查以确保它非零），请尝试：

[ [ [ myToolBar items ] objectAtIndex: myBarButtonItemIndex ] setEnabled:(NO) ];

回答by DavidCollinsNZ

I used a different solution (Swift 4.2) for my rightBarButtonItems.

我为我的 rightBarButtonItems 使用了不同的解决方案（Swift 4.2）。

I had 3 buttons so used a for loop, then made an extension of UINavigationItem so I could use it throughout my app.

我有 3 个按钮，因此使用了 for 循环，然后对 UINavigationItem 进行了扩展，以便我可以在整个应用程序中使用它。

extension UINavigationItem {
func setRightBarButtonItems(isEnabled:Bool){
    for button in self.rightBarButtonItems ?? [UIBarButtonItem()] {
        button.isEnabled = isEnabled
    }
}

Then i can call it from my TableViewController

然后我可以从我的 TableViewController 调用它

navigationItem.setRightBarButtonItems(isEnabled: false)

回答by ioopl

In my case (Swift) I had 2 barButtonItems added as an array - so to disable them this did the trick

就我而言（Swift），我将 2 个 barButtonItems 添加为一个数组 - 因此禁用它们就可以了

    navigationItem.rightBarButtonItems?.first?.enabled = false
    navigationItem.rightBarButtonItems?.last?.enabled = false