Question

情况：我在Watch应用中使用openParentApplication来呼叫主应用中的handleWatchKitExtensionRequest。这在模拟器中运行良好，当iPhone应用程序处于活动/打开状态时，它也适用于实际设备（Apple Watch和iPhone）。

问题：当我在实际设备（Apple Watch和iPhone）上运行时，handleWatchKitExtensionRequest在主iPhone应用未激活时不会将数据返回openParentApplication /打开。

WatchKit扩展中的InterfaceController.m中的代码：

NSDictionary *requst = @{ @"request" : @"getData" };
[InterfaceController openParentApplication:requst
                                     reply:^( NSDictionary *replyInfo, NSError *error ) {
                                        // do something with the returned info
                                     }];

iPhone主应用程序的app委托中的代码：

- (void)application:(UIApplication *)application handleWatchKitExtensionRequest:(NSDictionary *)userInfo reply:(void ( ^)( NSDictionary * ))reply
{
  if ( [[userInfo objectForKey:@"request"] isEqualToString:@"getData"] )
  {
    // get data
    // ...
    reply( data );
  }
}

Answer 1

当iPhone上的主应用程序未激活时，可能无法访问reply()，因为之前操作系统已将后台任务杀死。

解决方案是在handleWatchKitExtensionRequest中明确启动- (void)application:(UIApplication *)application handleWatchKitExtensionRequest:(NSDictionary *)userInfo reply:(void ( ^)( NSDictionary * ))reply { __block UIBackgroundTaskIdentifier watchKitHandler; watchKitHandler = [[UIApplication sharedApplication] beginBackgroundTaskWithName:@"backgroundTask" expirationHandler:^{ watchKitHandler = UIBackgroundTaskInvalid; }]; if ( [[userInfo objectForKey:@"request"] isEqualToString:@"getData"] ) { // get data // ... reply( data ); } dispatch_after( dispatch_time( DISPATCH_TIME_NOW, (int64_t)NSEC_PER_SEC * 1 ), dispatch_get_global_queue( DISPATCH_QUEUE_PRIORITY_DEFAULT, 0 ), ^{ [[UIApplication sharedApplication] endBackgroundTask:watchKitHandler]; } ); }中的后台任务。如果后台任务是这样启动的，它最多可以运行180秒。这可以确保iPhone上的主应用程序在发送回复之前不会被暂停。

iPhone主应用程序的app委托中的代码：

- (void)application:(UIApplication *)application handleWatchKitExtensionRequest:(NSDictionary *)userInfo reply:(void ( ^)( NSDictionary * ))reply
{ 
    __block UIBackgroundTaskIdentifier watchKitHandler;

    watchKitHandler = [[UIApplication sharedApplication] beginBackgroundTaskWithName:@"backgroundTask"
                                                               expirationHandler:^{
                                                                   watchKitHandler = UIBackgroundTaskInvalid;
                                                               }];  

   NSMutableDictionary *response = [NSMutableDictionary dictionary];

   dispatch_semaphore_t sema = dispatch_semaphore_create(0);

   [ClassObject getDataWithBlock:^(BOOL succeeded, NSError *error){

        if (succeeded)
        {
            [response setObject:@"update succeded" forKey:@"updateKey"];
        }
        else
        {
            if (error)
            {
                [response setObject:[NSString stringWithFormat:@"update failed: %@", error.description] forKey:@"updateKey"]; 
            }
            else
            {
                [response setObject:@"update failed with no error" forKey:@"updateKey"];
            }
        }

        reply(response);
        dispatch_semaphore_signal(sema);
    }];

    dispatch_semaphore_wait(sema, DISPATCH_TIME_FOREVER);

    dispatch_after(dispatch_time( DISPATCH_TIME_NOW, (int64_t)NSEC_PER_SEC * 1), dispatch_get_global_queue( DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
    [[UIApplication sharedApplication] endBackgroundTask:watchKitHandler];
  });
}

如果您需要异步获取数据，请使用以下方法确保该方法不会立即返回（不调用回复）：

function AddEventListeners() {
    document.getElementById('txtHangman').addEventListener('keypress', TextHangman.bind(this), false);
}

如何正确使用“openParentApplication”和“handleWatchKitExtensionRequest”以便调用“reply（）”？

1 个答案: