ios - AppDelegate 没有响应 NSNotification

Question

我想使用我的应用的 AppDelegate 发布 CRToast 通知

这是我添加观察者的方式。

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
[[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(noConnectionNotification)
                                                 name:@"No_Connection_Available" object:nil];

}

这是它应该调用的方法

-(void)noConnectionNotification{
     NSLog(@"received notification");
    NSString *notificationString = @"Unable to reach server. Changes will be cached.";
    NSDictionary *options = @{kCRToastTextKey : notificationString,
                              kCRToastNotificationTypeKey : @(CRToastTypeStatusBar),
                              kCRToastTextAlignmentKey : @(NSTextAlignmentCenter),
                              kCRToastBackgroundColorKey : [UIColor redColor],
                              kCRToastAnimationInDirectionKey : @(CRToastAnimationDirectionTop),
                              kCRToastAnimationOutDirectionKey : @(CRToastAnimationDirectionTop),
                              kCRToastTimeIntervalKey : @(2),
                              };
    [CRToastManager showNotificationWithOptions:options
                                completionBlock:nil];
}

以及我如何从不同的类(class)发布通知:

 dispatch_async(dispatch_get_main_queue(), ^{
       [[NSNotificationCenter defaultCenter] postNotificationName:@"No_Connection_Available" object:nil];
        });
    }

该方法不会被调用。如果我让我的各种 View Controller 之一成为观察者，那个会收到通知，但 AppDelegate 不是。是否不可能使 AppDelegate 成为 NSNotification 观察者？

Answer 1

您在收到通知时调用的方法需要有 NSNotification争论。因此，该方法应如下所示:

-(void)noConnectionNotification:(NSNotification*)notification {
     NSLog(@"received notification");
    NSString *notificationString = @"Unable to reach server. Changes will be cached.";
    NSDictionary *options = @{kCRToastTextKey : notificationString,
                              kCRToastNotificationTypeKey : @(CRToastTypeStatusBar),
                              kCRToastTextAlignmentKey : @(NSTextAlignmentCenter),
                              kCRToastBackgroundColorKey : [UIColor redColor],
                              kCRToastAnimationInDirectionKey : @(CRToastAnimationDirectionTop),
                              kCRToastAnimationOutDirectionKey : @(CRToastAnimationDirectionTop),
                              kCRToastTimeIntervalKey : @(2),
                              };
    [CRToastManager showNotificationWithOptions:options
                                completionBlock:nil];
}

然后，添加观察者应该如下所示:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
[[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(noConnectionNotification:)
                                                 name:@"No_Connection_Available" object:nil];

}

注意 @selector 中方法名称后面的冒号。称呼。