iOS Push Notifications - update badge without aler

2020-02-21 10:29发布

问题:

Is there a way to update the number in the badge without showing an alert or opening the app?

I am writing an app that should always display the current number of unread messages in the icon badge, but I want to do so without displaying any alerts to the user.

I am developing for iOS 5.0+.

EDIT: To be more clear, I am asking about a way to do this when the app is not running. I want the server to push a new badge number without showing an alert.. Is this possible?

回答1:

You can do it. It is possible to send a push notification without an alert. You can even register your application just to badge notifications, in which case the provider server won't even be able to send alerts or sounds.

The Notification Payload

Each push notification carries with it a payload. The payload specifies how users are to be alerted to the data waiting to be downloaded to the client application. The maximum size allowed for a notification payload is 256 bytes; Apple Push Notification Service refuses any notification that exceeds this limit. Remember that delivery of notifications is “best effort” and is not guaranteed.

For each notification, providers must compose a JSON dictionary object that strictly adheres to RFC 4627. This dictionary must contain another dictionary identified by the key aps. The aps dictionary contains one or more properties that specify the following actions:

An alert message to display to the user

A number to badge the application icon with

A sound to play

Note that it says one or more of the properties. The alert property is optional. You can even send a notification with an empty aps dictionary (i.e. send only custom properties).

Example 5. The following example shows an empty aps dictionary; because the badge property is missing, any current badge number shown on the application icon is removed. The acme2 custom property is an array of two integers.

{

    "aps" : {

    },

    "acme2" : [ 5,  8 ]

}

The only alert the user will see it the alert that asks him/her whether to allow push notifications. That alert will only be displayed the first time the app is launched after installation.

In this example you register to non alert notifications (badges and sounds only) :

Listing 2-3  Registering for remote notifications

- (void)applicationDidFinishLaunching:(UIApplication *)app {

   // other setup tasks here....

    [[UIApplication sharedApplication] registerForRemoteNotificationTypes:(UIRemoteNotificationTypeBadge | UIRemoteNotificationTypeSound)];

}



// Delegation methods

- (void)application:(UIApplication *)app didRegisterForRemoteNotificationsWithDeviceToken:(NSData *)devToken {

    const void *devTokenBytes = [devToken bytes];

    self.registered = YES;

    [self sendProviderDeviceToken:devTokenBytes]; // custom method

}



- (void)application:(UIApplication *)app didFailToRegisterForRemoteNotificationsWithError:(NSError *)err {

    NSLog(@"Error in registration. Error: %@", err);

}

All quotes are taken from the Apple Local and Push notifications programming guide.



回答2:

you should use applicationIconBadgeNumber for locally handling your app badge number

[UIApplication sharedApplication].applicationIconBadgeNumber = number_of_notifications;

I don't think it is possible to do without alert as far as adding badge counter from remote notification. You should read about APN Service, in your case you might register for UIRemoteNotificationTypeBadge you should read about Local & Push Notification Programming guide



回答3:

You can use

[UIApplication sharedApplication].applicationIconBadgeNumber = aNumber;


回答4:

-(void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo

{

    [[UIApplication sharedApplication] setApplicationIconBadgeNumber:0];
}

use this method....this will help u.