尽管声明它们是目标 c ios 8，但不允许显示警报

Posted 2023-02-24

【中文标题】尽管声明它们是目标 c ios 8，但不允许显示警报

【英文标题】：not allowing alerts to be shown despite declaring them objective c ios 8

【发布时间】：2015-09-23 09:42:19

【问题描述】：

我正在尝试以 Xcode 7.1 beta 中的警报样式声明通知，但我无法让它工作。我已经尝试了多种方法，但我就是无法让它们注册。我得到的错误日志是这样的：

尝试安排本地通知 触发日期 = 2015 年 9 月 23 日星期三晚上 8:08:03 新西兰标准时间，时区 = (null)，重复间隔 = 0，重复计数 = UILocalNotificationInfiniteRepeatCount，下一个触发日期 = (null), user info = (null) 带有警报但未获得用户显示警报的权限

这是我正在使用的代码：

    - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions

    // Override point for customization after application launch.
    return YES;
    //

    if ([UIApplication instancesRespondToSelector:@selector(registerUserNotificationSettings:)]) 
        [[UIApplication sharedApplication] registerUserNotificationSettings:[UIUserNotificationSettings settingsForTypes:UIUserNotificationTypeAlert|UIUserNotificationTypeSound|UIUserNotificationTypeBadge
                                                                                                              categories:nil]];
    

这些是我尝试过的其他无用的：

 [[UIApplication sharedApplication] registerUserNotificationSettings:    [UIUserNotificationSettings settingsForTypes:(UIUserNotificationTypeBadge | UIUserNotificationTypeSound | UIUserNotificationTypeAlert) categories:nil]]; 

[application registerUserNotificationSettings:[UIUserNotificationSettings settingsForTypes:UIUserNotificationTypeAlert|UIUserNotificationTypeBadge|UIUserNotificationTypeSound categories:nil]];

我应该怎么做才能解决这个问题？谢谢。

【问题讨论】：

"返回是；"应该在最后（在 if 条件之后）

【参考方案1】：

正如错误消息所述，您尝试在获得用户许可之前安排本地通知。问题是您在返回调用之后放置了请求权限的代码，因此它永远不会被调用。你的application:didFinishLaunchingWithOptions: 应该是这样的：

    - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
    
        if ([UIApplication instancesRespondToSelector:@selector(registerUserNotificationSettings:)]) 
        
            [[UIApplication sharedApplication] registerUserNotificationSettings:[UIUserNotificationSettings settingsForTypes:UIUserNotificationTypeAlert|UIUserNotificationTypeSound|UIUserNotificationTypeBadge
                                                                                                                  categories:nil]];
        

        return YES;
    

【参考方案2】：

在return 语句上方添加这段代码。在return 之后，以下行不会被执行

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions     


if ([application respondsToSelector:@selector(registerUserNotificationSettings:)]) 

    [application registerUserNotificationSettings:[UIUserNotificationSettings settingsForTypes:UIUserNotificationTypeAlert|UIUserNotificationTypeBadge|UIUserNotificationTypeSound categories:nil]];     


return YES