如果应用程序已经在运行，如何处理推送通知？答案

【问题标题】：How to handle push notifications if the application is already running?如果应用程序已经在运行，如何处理推送通知？
【发布时间】：2010-12-06 00:00:38
【问题描述】：

如果应用程序已经在运行，我们如何处理推送通知？如果应用程序正在运行，我想显示一个警报（而不是推送通知警报）。仅当应用程序未运行时，才会显示推送通知警报。

另外，如果我向 APNs 发送有效负载，如何创建带有取消按钮的警报？

【问题讨论】：

标签： ios objective-c push-notification apple-push-notifications

【解决方案1】：

你可以实现application:didReceiveRemoteNotification:

这是一个可能的示例代码：

- (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];
  }

【讨论】：

谢谢。苹果对此真的很不方便。
@DGund 真的吗？如果你尝试编写 Android 的推送（ GCM / C2DM ），你会发现它要复杂得多。
@notnoop 代码有问题。应将if(alert) 替换为if(message)
请查看 TomTom 关于检查状态的回答。那将是更好的，非hacky的方式。只是为了其他人的利益而分享。

【解决方案2】：

您可以检查 UIApplication 的状态。做这样的检查

 - (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
    }
}

【讨论】：

yourMessage 未定义。你至少应该说明如何从userInfo获取消息。
@ShivanRaptor - 我认为这不是问题的重点吗？这是更好的方法——而不是像检查 userInfo 是字符串还是字典那样的 hack。
很好的答案，选中的那个不起作用，想知道为什么它被认为是好的而不是这个。

【解决方案3】：

“alert”键不会直接在 userInfo 字典下，您需要获取另一个名为“aps”的字典，然后从“aps”字典中获取“alert”或“body”。

【讨论】：

【解决方案4】：

迭代 3 级有效载荷

 - (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);
        } 

    }
  }

}

结果是：

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

【讨论】：