Ios [ViewController行]：发送到collectionView didSelectItemAtIndexPath中实例的无法识别的选择器

我试图通过segue将集合视图中的选定对象传递给另一个视图控制器。当我单击集合视图中的一个单元格时，应用程序崩溃，并出现以下错误：

由于未捕获的异常“NSInvalidArgumentException”而终止应用程序，原因：'-[ViewController行]：未识别的选择器已发送到实例0x136d1fbf0

我是这样做的：

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    _friends = [[NSMutableArray alloc] init];
    [self refresh];
}

- (void)refresh {
    PFQuery *query = [PFQuery queryWithClassName:@"People"];
    [query orderByDescending:@"createdAt"];
    [query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
        if (error) {
            NSLog(@"Error: %@ %@", error, error.userInfo);
        } else {
            [self.collectionView reloadData];
        }
    }];
}

-(void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath {

    if (indexPath.section == 0) {
        NSLog(@"Do nothing");
    } else {
        [self performSegueWithIdentifier:@"profilePush" sender:self];
    }
}

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
    FriendsTableViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"FriendsTableViewCell" forIndexPath:indexPath];

        cell.friendsDelegate = self;

        PFObject *friendObj = [_friends objectAtIndex:indexPath.row];

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

         cell.nameL.text = friendObj[@"username"];

         return cell;
}

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {
    if (section == 0) {
         return 3;
    } else {
        return _friends.count;
    }
}

- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView {
    return 2;
}

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    if ([segue.identifier isEqualToString:@"profilePush"]) {
        NSIndexPath *indexPath = (NSIndexPath*)sender;
        ProfilePopupViewController *person = segue.destinationViewController;
        person.user = [_friends objectAtIndex:indexPath.row];

        //.user is a PFObject in the next view controller
    }
}

@end

---

在

prepareforsgue:sender:

中，

sender

不是

indepath

。使用

indexPathsForSelectedItems

来识别所选单元格

错误来自此处

prepareForSegue中的发送方是viewController

您正在将viewController强制转换为NSIndexPath

 NSIndexPath *indexPath = (NSIndexPath*)sender;
 ProfilePopupViewController *person = segue.destinationViewController;
 person.user = [_friends objectAtIndex:indexPath.row];