How to handle push notifications if the application is already running?

How do we handle push notifications if the application is already running ? I want to show an alert if the application is running (instead of a push notification alert). Only if the application is not running, then show a push notification alert.

Also, if I send a payload to APNs, how can I create an alert with a cancel butt开发者_JAVA百科on?

You can implement application:didReceiveRemoteNotification:

Here is a possible sample code:

- (void)application:(UIApplication *)application
   didReceiveRemoteNotification:(NSDictionary *)userInfo
{
  NSString *message = nil;
  id alert = [userInfo objectForKey:@"alert"];
  if ([alert isKindOfClass:[NSString class]]) {
    message = alert;
  } else if ([alert isKindOfClass:[NSDictionary class]]) {
    message = [alert objectForKey:@"body"];
  }
  if (alert) {
    UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"Title"
                                       message:@"AThe message."  delegate:self
                             cancelButtonTitle:@"button 1"
                             otherButtonTitles:@"button", nil];
    [alertView show];
    [alertView release];
  }

You can check for the state of the UIApplication. Just do a check like this

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

    UIApplicationState state = [application applicationState];
    if (state == UIApplicationStateActive)
    {

            UIAlertView *alert = [[[UIAlertView alloc] initWithTitle:@"xxx" message:yourMessage delegate:self cancelButtonTitle:@"Done" otherButtonTitles: @"Anzeigen", nil] autorelease];
            [alert setTag: 2];
            [alert show];
    }
    else {
        // Push Notification received in the background
    }
}

"alert" key will not be there directly under the userInfo dictionary, you need to get another dictionary with name "aps" and then get the "alert" or "body" from "aps" dictionary.

Iterating the 3 levels of payload

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

for (id key in userInfo) {
    NSLog(@"key: %@, value: %@", key, [userInfo objectForKey:key]);
    NSString *message = nil;

NSDictionary *aps = [NSDictionary dictionaryWithDictionary:(NSDictionary *) [userInfo objectForKey:key] ];   
    for (id key1 in aps){
         NSLog(@"key1: %@", key1);
        id alert = [aps objectForKey:key1];
        if ([alert isKindOfClass:[NSDictionary class]]) {
            message = [alert objectForKey:@"body"];
             NSLog(@"body: %@, value: %@", key1, message);
            message = [alert objectForKey:@"loc-args"];
            NSLog(@"loc-args: %@, value: %@", key1, message);
            NSArray *args = (NSArray *) [alert objectForKey:@"loc-args"] ;
                for (id key2 in args){
                    NSLog(@"key2: %@, value: ", key2);
                }
            message = [alert objectForKey:@"action-loc-key"];
            NSLog(@"action-loc-key: %@, value: %@", key1, message);

        }
        else if ([alert isKindOfClass:[NSArray class]]) {
            for (id key2 in key1){
                NSLog(@"key2: %@, value: %@", key2, [key1 objectForKey:key2]);
            }
        }
        else if([key1 isKindOfClass:[NSString class]]) {
            message = [aps objectForKey:key1];
            NSLog(@"key1: %@, value: %@", key1, message);
        } 

    }
  } 

}

The result is:

2012-01-27 20:38:09.599 SPush[4181:707] key: aps, value: {
alert =     {
    "action-loc-key" = Open;
    body = test;
    "loc-args" =         (
        1000,
        2000
    );
};
badge = 0;
"content-available" = 10;
sound = default;
}
2012-01-27 20:38:13.133 SPush[4181:707] key1: alert
2012-01-27 20:38:13.134 SPush[4181:707] body: alert, value: test
2012-01-27 20:38:13.137 SPush[4181:707] loc-args: alert, value: (
1000,
2000
)
2012-01-27 20:38:13.138 SPush[4181:707] key2: 1000, value: 
2012-01-27 20:38:13.139 SPush[4181:707] key2: 2000, value: 
2012-01-27 20:38:13.140 SPush[4181:707] action-loc-key: alert, value: Open
2012-01-27 20:38:13.141 SPush[4181:707] key1: sound
2012-01-27 20:38:13.143 SPush[4181:707] key1: sound, value: default
2012-01-27 20:38:13.144 SPush[4181:707] key1: badge
2012-01-27 20:38:13.145 SPush[4181:707] key1: badge, value: 0
2012-01-27 20:38:13.146 SPush[4181:707] key1: content-available
2012-01-27 20:38:13.147 SPush[4181:707] key1: content-available, value: 10