1

如何实现获取UIAccessibilityVoiceOverStatusChanged通知?

我尝试如下,但没有任何反应:

NSNotificationCenter *nc = [NSNotificationCenter defaultCenter];
[nc addObserver:self selector:@selector(notified:) name:UIAccessibilityVoiceOverStatusChanged object:self];
4

3 回答 3

0

这看起来很合理,除了 object:self 应该是 object:nil 吗?另一件事是确保您的签名是正确的:

- (void)voiceOverStatusChanged: (NSNotification *)notification;
于 2012-01-20T03:11:29.883 回答
0

我认为您可以尝试使用正确的选择器签名在 awakeFromNib 方法中添加观察者。

像这样的东西会起作用

- (void)awakeFromNib {
    [super awakeFromNib];
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(voiceOverChanged)
                                                 name:UIAccessibilityVoiceOverStatusChanged
                                               object:nil];
    [self voiceOverChanged];
}

- (void)dealloc {
    [[NSNotificationCenter defaultCenter] removeObserver:self name:UIAccessibilityVoiceOverStatusChanged object:nil];
}

- (void)voiceOverChanged {
// Your actions here
}
于 2015-09-07T11:07:46.163 回答
0

您可以使用代码获取 UIAccessibilityVoiceOverStatusChanged 通知

- (void)viewDidLoad {
        [super viewDidLoad];
        [[NSNotificationCenter defaultCenter]
            addObserver:self
            selector:@selector(didChangeVoiceOverStatus:)
            name:UIAccessibilityVoiceOverStatusChanged
            object:nil];
    }

- (void)didChangeVoiceOverStatus:(NSNotification *)notification {
        if (UIAccessibilityIsVoiceOverRunning()) {
            NSLog(@"VoiceOver is ON.");
        } else {
            NSLog(@"VoiceOver is OFF.");
        }
    }
于 2017-01-04T04:15:38.927 回答