显示 iOS 徽章编号/处理未读消息 (xCode - OBJECTIVE-C)

Displaying iOS badge number / Handling unread messages (xCode - OBJECTIVE-C)

我想更新收件箱徽章以显示未读消息的数量(我的消息不会自毁,应用类似于 iOS 消息)。

当用户点击一条消息并返回到收件箱选项卡时,应更新徽章。另外,我想将未读单元格的背景颜色标记为不同于已读单元格的背景颜色……这样用户就知道哪些已读,哪些未读。

我有一些工作代码,但现在我得到:

"Warning: A long-running operation is being executed on the main thread. Break on warnBlockingOperationOnMainThread() to debug."

这是我用来更新未读消息的代码:

PFQuery *query = [PFQuery queryWithClassName:@"Messages"];
    [query whereKey:@"recipientIds" equalTo:[[PFUser currentUser] objectId]];
    [query orderByDescending:@"createdAt"];
    [query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
        if (error) {
            NSLog(@"Error: %@ %@", error, [error userInfo]);
        } else {
            // messages were found!
            self.messages = objects;

            //find unread messages
            [query whereKey:@"readBy" notEqualTo:[[PFUser currentUser] objectId]];
            self.unreadMessages = [query findObjects];

            // set badge # to number of msgs
            if (self.unreadMessages.count > 0) {

                [[self navigationController] tabBarItem].badgeValue = [NSString stringWithFormat:@"%lu", (unsigned long)self.unreadMessages.count];
            }

            [self.tableView reloadData];

更新单元格的代码:

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"Cell" forIndexPath:indexPath];

PFObject *message = [self.messages objectAtIndex:indexPath.row];
cell.textLabel.text = [message objectForKey:@"senderEmail"];

if ([self.unreadMessages containsObject:message]) {
    // color background gray, bold the font
}else{
   // leave cell alone
}
[query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error)  
{
    if (!error) 
    {
        self.unreadMessages = [NSMutableArray arrayWithArray:objects];
       // set badge # to number of msgs
        if (self.unreadMessages.count > 0) 
        { 
            [[self navigationController] tabBarItem].badgeValue = [NSString stringWithFormat:@"%lu", (unsigned long)self.unreadMessages.count];
        }
        [self.tableView reloadData];
    }
}