Question

我的问题是，如果应用在后台并且通知到达，我从图标打开了应用;应用程序恢复它状态，但我想在这种情况下更新屏幕数据。有通知到达时有没有办法在后台更新数据？

以下是我用于处理此案例的代码：

ViewController.m文件代码：

 - (void)viewDidLoad {
        [super viewDidLoad];
        [[NSNotificationCenter defaultCenter] addObserver:self
                                                 selector:@selector(appIsComingFromBackground:)
                                                     name:UIApplicationDidBecomeActiveNotification
                                                   object:nil];
        // Do any additional setup after loading the view, typically from a nib.
    }
    - (void) appIsComingFromBackground:(NSNotification *) note {
        // code
        NSString *hasMessage = [[NSUserDefaults standardUserDefaults] objectForKey:@"alertmsg"];
        if([hasMessage length]!=0)
        {
            _labelText.text = hasMessage;
             [[NSUserDefaults standardUserDefaults] setObject:@"" forKey:@"alertmsg"];
        }
        else{
             _labelText.text = @"";
        }
    }

AppDelegate.m文件代码：

- (void)application:(UIApplication *)application didReceiveLocalNotification:(UILocalNotification *)notification
{

    if (application.applicationState == UIApplicationStateActive) {

    }
    else if(application.applicationState == UIApplicationStateBackground || application.applicationState == UIApplicationStateInactive)
    {
        [[NSUserDefaults standardUserDefaults] setObject:notification.alertTitle forKey:@"alertmsg"];
    }
    NSLog(@"Alert Message: %@", notification.alertTitle);
    NSLog(@"Alert Body: %@", notification.alertBody);
}

Answer 1

应用程序未运行

当应用未运行时，用户会通过以下方式查看通知，具体取决于通知设置：

显示提醒或横幅
标记应用图标
播放声音

点击通知的操作按钮，用户将启动该应用。在这种情况下，应用程序：didFinishLaunchingWithOptions：调用应用程序委托的方法。

 - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
// Override point for customization after application launch.

// Handle launching from a notification
UILocalNotification *locationNotification = [launchOptions objectForKey:UIApplicationLaunchOptionsLocalNotificationKey];
if (locationNotification) {
    // Set icon badge number to zero
    application.applicationIconBadgeNumber = 0;
}

return YES;
}

Applicaton正在前台运行

如果应用程序在通知发送时正在运行，则屏幕上不会显示任何警报。应用程序自动调用其委托的应用程序：didReceiveLocalNotification：method。

- (void)application:(UIApplication *)application didReceiveLocalNotification:(UILocalNotification *)notification
{
UIApplicationState state = [application applicationState];
if (state == UIApplicationStateActive) {

}

// Request to reload table view data
[[NSNotificationCenter defaultCenter] postNotificationName:@"reloadData" object:self];

// Set icon badge number to zero
application.applicationIconBadgeNumber = 0;
 }

应用程序正在后台运行

此应用已推出，但用户切换到另一个应用。通知被触发后，用户通常会在屏幕顶部看到警报横幅。当点击它时，应用程序将被带到前台。与应用程序在前台运行的情况类似，应用程序自动调用其委托的应用程序：didReceiveLocalNotification：method。

Answer 2

 In Appdelegate

  - (void)application:(UIApplication *)application didReceiveLocalNotification:   (UILocalNotification *)notification
{

if (application.applicationState == UIApplicationStateActive) {

}
else if(application.applicationState == UIApplicationStateBackground || application.applicationState == UIApplicationStateInactive)
{
  //  [[NSUserDefaults standardUserDefaults] setObject:notification.alertTitle forKey:@"alertmsg"];

[[NSNotificationCenter defaultCenter]postNotificationName:@"PushNotificationReceived" object:nil userInfo:userInfo];

}
NSLog(@"Alert Message: %@", notification.alertTitle);
NSLog(@"Alert Body: %@", notification.alertBody);

 }


 In view controller:

 -(void)viewDidLoad
{
     [[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(doChangesWhatdidYouWant:) name:@"PushNotificationReceived" object:nil];
 }

 -(void)doChangesWhatdidYouWant:(NSNotification *)notification{
 //Todo
 }

iOS：如果应用程序在后台并且到达本地通知;哪个方法会自动调用？

2 个答案: