How to delete all local notifications when an appl

问题:

Let's say I set 5 local notification for an iPhone application, then the user deletes the app. If the app is installed again, it shows the previous notifications.

I know the following code deletes all notifications

[[UIApplication sharedApplication] cancelAllLocalNotifications];

But where do I put that code so that it executes when the application is deleted?

Or any other way to solve this problem.

回答1:

As others have mentioned, I think the best way to accomplish this is to have a flag in didFinishLaunchingWithOptions in the application delegate that checks if it is the first launch or not.

If the app is being launched for the first time, you can call

[[UIApplication sharedApplication] cancelAllLocalNotifications];

This will cancel any existing notifications.

For example:

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

    // this flag will need to be stored somewhere non-volatile such as using CoreData 
    // or user defaults
    if(flag == nil || [flag count] ==0){ 

       [[UIApplication sharedApplication] cancelAllLocalNotifications];

       // update your flag so that it fails this check on any subsequent launches
       flag = 1;
    }
{

回答2:

Here's what I did:

In Your AppDelegate

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

    //Check if its first time
    if (![[NSUserDefaults standardUserDefaults] objectForKey:@"is_first_time"]) {
        [application cancelAllLocalNotifications]; // Restart the Local Notifications list
        [[NSUserDefaults standardUserDefaults] setObject:[NSNumber numberWithBool:YES] forKey:@"is_first_time"];
    }

    return YES;
}

Hope it helps!

回答3:

For swift 3.0 you can use

if (isFirstLaunch){  
  UNUserNotificationCenter.current().removeAllPendingNotificationRequests()
}

Then add this method to check if this is the first run

var isFirstLaunch: Bool {
    get {
        if     (NSUserDefaults.standardUserDefaults().objectForKey("firstLaunchDate") == nil) {
            NSUserDefaults.standardUserDefaults().setObject(NSDate(),     forKey: "firstLaunchDate")
            NSUserDefaults.standardUserDefaults().synchronize()
            return true
        }
        return false
    }
}

回答4:

You can use UIPasteboard to store a flag as DerekH already mentioned.
Something link this:

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

    if ([self mustCancelNotifications]) {
        [application cancelAllLocalNotifications];
        [self removeTag];
    } else {
        // Set your local notifications
        [self setFlag];
    }

    //...   

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

- (BOOL)mustCancelNotifications
{
    UIPasteboard *past = [UIPasteboard generalPasteboard];
    NSString *s = [past valueForPasteboardType:@"my_app_local_notifications"];
    if (s) {
        return YES;
    }
    return NO;
}

- (void)setFlag
{
    UIPasteboard *past = [UIPasteboard generalPasteboard];
    [past setValue:@"dummy" forPasteboardType:@"my_app_local_notifications"];
}

- (void)removeFlag
{
    UIPasteboard *past = [UIPasteboard generalPasteboard];
    [past setData:nil forPasteboardType:@"my_app_local_notifications"];
}

回答5:

Go to your appDelegate.m, in function «didFinishLaunchingWithOptions» add this code:

application.applicationIconBadgeNumber = 0;