ios - 无法确定用户是否可以在 IO 中收到我的通知

Question

我想以编程方式找出用户是否启用了推送通知。

我正在使用这段代码：

 UIRemoteNotificationType status = [[UIApplication sharedApplication] enabledRemoteNotificationTypes];
    if (status == UIRemoteNotificationTypeNone)
    {
        NSLog(@"User doesn't want to receive push-notifications");
    } 

如果我这样做：

1. 当应用程序请求许可时，我按确定，然后从设置中将通知中心设置为关闭，将警报样式设置为无，我无法收到通知，但我没有看到 NSLog。

2. 如果通知中心处于关闭状态并且警报样式不同于无，我看不到 NSLog，但我可以接收通知。

有人可以解释 1,2 的行为，我应该做什么检查？

Answer 1

UIRemoteNotificationType notificationTypes = [[UIApplication sharedApplication] enabledRemoteNotificationTypes];

notificationTypes has the integer code which will help us to find what are the remote notification enabled. For that, we need to understand the UIRemoteNotificationType,

typedef enum {
   UIRemoteNotificationTypeNone    = 0,
   UIRemoteNotificationTypeBadge   = 1 << 0,
   UIRemoteNotificationTypeSound   = 1 << 1,
   UIRemoteNotificationTypeAlert   = 1 << 2,
   UIRemoteNotificationTypeNewsstandContentAvailability = 1 << 3
} UIRemoteNotificationType; 

According to the Bitwise left shift calculation, following are the values,

• UIRemoteNotificationTypeNone = 0
• UIRemoteNotificationTypeBadge = 1
• UIRemoteNotificationTypeSound = 2
• UIRemoteNotificationTypeAlert = 4
• UIRemoteNotificationTypeNewsstandContentAvailability = 8

Following code will help us to find what are the remote notification enabled for your app,

    if (notificationTypes == UIRemoteNotificationTypeNone) {
        // Do what ever you need to here when notifications are disabled
        NSLog(@"User doesn't want to receive push-notifications");
    } else if (notificationTypes == UIRemoteNotificationTypeBadge) {
        // Badge only
        NSLog(@"Badges Only");
    } else if (notificationTypes == UIRemoteNotificationTypeAlert) {
        // Alert only
        NSLog(@"Alerts only");
    } else if (notificationTypes == UIRemoteNotificationTypeSound) {
        // Sound only
        NSLog(@"Sound Only");
    }
    else if (notificationTypes == UIRemoteNotificationTypeNewsstandContentAvailability) {
        // NewsstandContentAvailability only
        NSLog(@"NewsstandContentAvailability Only");
    }else if (notificationTypes == 5)//Badge(1)+Alert(4)=5 {
        // Badge & Alert
        NSLog(@"Badges and Alert");
    } else if (notificationTypes == 3)//Badge(1)+Sound(2)=3 {
        // Badge & Sound
        NSLog(@"Badges and Sound");
    } else if (notificationTypes == 6)//Alert(4)+Sound(2)=6 {
        // Alert & Sound
        NSLog(@"Alert and Sound");
    } else if (notificationTypes == 7)//Badge(1)+Alert(4)+Sound(2)=7 {
        // Badge, Alert & Sound
        NSLog(@"Badge, Alert & Sound");
    }
    else if (notificationTypes == 10)//Sound(2)+NewsstandContentAvailability(8)=10 {
        // Sound & NewsstandContentAvailability
        NSLog(@"Sound & NewsstandContentAvailability");
    }

Note: I haven't write all possible if-else statements. Please add according to your need.

Hope this will help you.