在選擇didSelectRowAtIndexPath中的收件人時錯誤的PFUser objectId Parse.com

Question

我目前正在構建一個照片通訊應用程序，用戶可以將照片發送給對方。拍攝照片時，您可以在新的View Controller中從UITableView中選擇收件人。

但每次我從列表中選擇一個人併發送照片時，它會得到錯誤的user.objectId。它似乎需要Friendship objectId，它是另一個類名爲Friendship的類，當它取用戶的objectId時。下面是我如何做它：

@implementation PickRecipientsViewController 

- (void)viewDidLoad { 
    [super viewDidLoad]; 

    self.recipients = [[NSMutableArray alloc] init]; 
    [_selectedImage setImage:_image]; 
    self.tableView.delegate = self; 

    [self refreshFriends]; 
} 

- (void)refreshFriends { 

    [__acceptedRequests removeAllObjects]; 
    PFQuery *friendsQuery = [self queryForFriends]; 
    PFQuery *acceptedRequestQuery = [self queryForAcceptedFriendRequests]; 
    PFQuery *friendRequestsQuery = [self queryForRequests]; 
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^{ 

     // Find friends 
     NSArray *objects = [friendsQuery findObjects]; 
     for (PFObject * obj in objects) { 
      [obj[@"user1"] fetchIfNeeded]; 
      [obj[@"user2"] fetchIfNeeded]; 
     } 
     _friends = [objects mutableCopy]; 

     // Find pending requests 
     objects = [friendRequestsQuery findObjects]; 
     for (PFObject *obj in objects) { 
      [obj[@"fromUser"] fetchIfNeeded]; 
     } 
     __friendRequests = [objects mutableCopy]; 

     // Find accepted requests 
     objects = [acceptedRequestQuery findObjects]; 
     for (PFObject *obj in objects) { 
      PFUser *to = (PFUser*)[obj[@"toUser"] fetchIfNeeded]; 
      [obj deleteEventually]; 
      [__acceptedRequests addObject:to[@"username"]]; 
     } 

     // show accepted requests 
     dispatch_async(dispatch_get_main_queue(), ^{ 
      [self.tableView reloadData]; 
      if (__acceptedRequests.count > 0) { 
       NSString *friends = __acceptedRequests[0]; 
       for (int i = 1; i < __acceptedRequests.count; ++i) { 
        friends = [friends stringByAppendingFormat:@", %@", __acceptedRequests[i]]; 
       } 
       friends = [friends stringByAppendingString:@" accepted your friend request"]; 

       UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"New Friends" message:friends delegate:self cancelButtonTitle:@"Wuhu" otherButtonTitles:nil, nil]; 
       alert.tag = kAlertTagAcceptedRequest; 
       [alert show]; 
      } 
     }); 
    }); 
} 

- (PFQuery *)queryForAcceptedFriendRequests { 
    PFUser *user = [PFUser currentUser]; 
    NSPredicate *predicate = [NSPredicate predicateWithFormat:@"status = %@ AND (fromUser = %@ AND toUser != %@)", @"approved", user, user]; 
    PFQuery *acceptedRequestQuery = [PFQuery queryWithClassName:@"FriendRequest" predicate:predicate]; 
    return acceptedRequestQuery; 
} 

- (PFQuery *)queryForFriends { 
    PFUser *user = [PFUser currentUser]; 
    NSPredicate *predicate = [NSPredicate predicateWithFormat:@"user1 = %@ AND user2 != %@ OR user1 != %@ AND user2 = %@", user, user, user, user]; 
    PFQuery *friendsQuery = [PFQuery queryWithClassName:@"Friendship" predicate:predicate]; 
    return friendsQuery; 
} 

- (PFQuery *)queryForRequests { 
    PFUser *user = [PFUser currentUser]; 
    NSPredicate *predicate = [NSPredicate predicateWithFormat:@"status = %@ AND (toUser = %@ AND fromUser != %@)", @"pending", user, user]; 
    PFQuery *friendRequests = [PFQuery queryWithClassName:@"FriendRequest" predicate:predicate]; 
    return friendRequests; 
} 

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

    PFUser *user = [self.friends objectAtIndex:indexPath.row]; 

    if([self.recipients containsObject:user.objectId]){ 
     cell.accessoryType = UITableViewCellAccessoryCheckmark; 
    }else{ 
     cell.accessoryType = UITableViewCellAccessoryNone; 
    } 

    PFObject *friendRequest = [_friends objectAtIndex:indexPath.row]; 
    PFUser *user1 = (PFUser *)friendRequest[@"user1"]; 
    PFUser *user2 = (PFUser *)friendRequest[@"user2"]; 

    if ([user1.username isEqualToString:[PFUser currentUser].username]) { 
     cell.nameL.text = user2[@"username"]; 

     [(PFFile*)user2[@"profilePic"] getDataInBackgroundWithBlock:^(NSData *data, NSError *error) { 
      if (error) {return;} 
      cell.profilePic.image = [UIImage imageWithData:data]; 
     }]; 

    } else if ([user2.username isEqualToString:[PFUser currentUser].username]) { 
     cell.nameL.text = user1[@"username"]; 

     [(PFFile*)user1[@"profilePic"] getDataInBackgroundWithBlock:^(NSData *data, NSError *error) { 
      if (error) {return;} 
      cell.profilePic.image = [UIImage imageWithData:data]; 
     }]; 
    } 
    return cell; 
} 

- (BOOL)isFriend:(PFUser *)user { 
    for (PFUser *friend in self.friends) { 
     if ([friend.objectId isEqualToString:user.objectId]) { 
      return YES; 
     } 
    } 
    return NO; 
} 

-(NSInteger)numberOfSectionsInTableView:(UITableView *)tableView { 
    return 1; 
} 

-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { 
    return _friends.count; 
} 

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath { 
    return 68; 
} 

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { 

    [self.tableView deselectRowAtIndexPath:indexPath animated:NO]; 

    UITableViewCell *cell = [self.tableView cellForRowAtIndexPath:indexPath]; 
    PFUser *user = [self.friends objectAtIndex:indexPath.row]; 

    if (cell.accessoryType == UITableViewCellAccessoryNone){ 
     cell.accessoryType = UITableViewCellAccessoryCheckmark; 
     [self.recipients addObject:user.objectId]; 
    } else{ 
     cell.accessoryType = UITableViewCellAccessoryNone; 
     [self.recipients removeObject:user.objectId]; 
    } 
} 

- (IBAction)sendImage { 

    PFObject *message = [PFObject objectWithClassName:@"Messages"]; 

    [message setObject:[PFUser currentUser] forKey:@"fromUser"]; 
    [message setObject:[PFUser currentUser] forKey:@"toUser"]; 
    [message setObject:@"image" forKey:@"fileType"]; 

    [message setObject:self.recipients forKey:@"recipientIds"]; 
    [message setObject:[[PFUser currentUser] objectId] forKey:@"senderId"]; 

    // Image 
    NSData *imageData = UIImageJPEGRepresentation(_image, 1.0); 
    NSString *filename = [NSString stringWithFormat:@"image.png"]; 
    PFFile *imageFile = [PFFile fileWithName:filename data:imageData]; 
    [message setObject:imageFile forKey:@"file"]; 

    [message saveInBackgroundWithBlock:^(BOOL succeeded, NSError *error) { 
     if (!error) { 

      // Dismiss the controller 
      [[[self presentingViewController] presentingViewController] dismissViewControllerAnimated:YES completion:nil]; 

     } else { 
      [SVProgressHUD showErrorWithStatus:@"Oh darn! Something went wrong :("]; 
     } 
    }]; 
} 

@end 

Answer 1

因爲_friends是Friendship對象的數組，當行被竊聽，你乾脆直接把它弄出來的陣列，並且沒有再從它那裏得到適當的用戶（就像您在配置單元標籤時所做的一樣）。

所以在tableView:didSelectRowAtIndexPath:你應該有這樣的：

BOOL adding = NO; 

if (cell.accessoryType == UITableViewCellAccessoryNone){ 
    cell.accessoryType = UITableViewCellAccessoryCheckmark; 
    adding = YES; 
} else { 
    cell.accessoryType = UITableViewCellAccessoryNone; 
} 

PFObject *friendRequest = [_friends objectAtIndex:indexPath.row]; 
PFUser *user1 = (PFUser *)friendRequest[@"user1"]; 
PFUser *user2 = (PFUser *)friendRequest[@"user2"]; 

PFUser *recipient = nil; 

if ([user1.username isEqualToString:[PFUser currentUser].username]) { 
    recipient = user2; 
} else if ([user2.username isEqualToString:[PFUser currentUser].username]) { 
    recipient = user1; 
} 

if (adding) { 
    [self.recipients addObject:recipient.objectId]; 
} else { 
    [self.recipients removeObject:recipient.objectId]; 
}