iOS - 当新数据发布到NSMutableArray时触发通知？

Question

我已经在我的服务器上设置了推送通知，并且一切正常。 E.g.我可以随时向所有用户发送通知（因为所有设备令牌都存储在我的数据库中）。也就是说，我想在应用程序中镜像的服务器上的数据更新时向设备发送推送通知（，例如，当新消息发布到服务器时）？

更具体地说：查看下面我用来在tableview中显示所有收到的消息的代码。我该如何做到这一点，以便登录的用户在self.messages更新时收到通知？

ViewController.m

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath 
{ 

    static NSString *PointsTableIdentifier = @"MyMessagesCell"; 

    MyMessagesCell *cell = (MyMessagesCell *)[tableView dequeueReusableCellWithIdentifier:PointsTableIdentifier]; 
    if (cell == nil) 
    { 
     NSArray *nib = [[NSBundle mainBundle] loadNibNamed:@"MyMessagesCell" owner:self options:nil]; 
     cell = [nib objectAtIndex:0]; 

    } 


    NSDictionary *receivedSubjectLine = [self.messages objectAtIndex:indexPath.row]; 

    NSString *messageSubject = [receivedSubjectLine objectForKey:@"node_title"]; 


    [cell.subjectLine setText:messageSubject]; 



    NSDictionary *fromUser = [self.messages objectAtIndex:indexPath.row]; 

    NSString *userName = [fromUser objectForKey:@"name"]; 

    [cell.senderName setText:userName]; 



    NSDictionary *receivedBody = [self.messages objectAtIndex:indexPath.row]; 

    NSString *messageBody = [receivedBody objectForKey:@"body"]; 

    [cell.fullMessage setText:messageBody]; 


    NSDictionary *receivedTime = [self.messages objectAtIndex:indexPath.row]; 

    NSString *timeStamp = [receivedTime objectForKey:@"swaptime"]; 

     NSLog(@"The timestamp is %@", timeStamp); 

    [cell.swapTime setText:timeStamp]; 

    return cell; 

} 

Answer 1

我在我的应用程序聊天不使用网络插座（我们还没有拥有它执行的时间），所以我们做的是刷新使用通知中心的UITableView。

在AppDelegate中我有这样的代码：

- (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo 
{ 
    [[NSNotificationCenter defaultCenter] postNotificationName:@"reloadTheTable" object:nil]; 
} 

然后在我的聊天类我有这样的代码登记在viewDidLoad中通知：

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(reloadTable:) name:@"reloadTheTable" object:nil]; 

然后选择调用服务器并刷新显示的数据：

- (void)reloadTable:(NSNotification *)notification 
{ 
    [[NSNotificationCenter defaultCenter] removeObserver:self]; 
    [self checkJson]; //This function loads the data and when it finish calls another method call loadTable 
} 

- (void)loadTable { 
    [_tvTable reloadData]; //this simply reload your UITableView 
} 

我也使用这个技术来重新加载时，应用程序来到前景：

- (void)applicationDidBecomeActive:(UIApplication *)application 
{ 
    // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface. 
    [[NSNotificationCenter defaultCenter] postNotificationName:@"reloadTheTable" object:nil]; 
} 

我希望这可以帮助你。