Obj-C：错误 __NSSingleObjectArrayI removeObjectAtIndex:]：无法识别的选择器发送到实例？

Question

我试图使用下面的代码从我的 NSDictionary 中删除一个数组（从我的表视图中删除一个对象），但是由于某种原因我在这一行崩溃了：

[self.friendData removeObjectAtIndex:indexPath.row];

出现此错误：

由于未捕获的异常“NSInvalidArgumentException”而终止应用程序，原因：“-[__NSSingleObjectArrayI removeObjectAtIndex:]：无法识别的选择器发送到实例 0x1c0618e20”

知道这是为什么以及解决方法是什么吗？请参阅 self.friendData 的控制台信息和下面的代码：

视图控制器.h

@property (weak, nonatomic) IBOutlet UISegmentedControl *segmentControl;
@property (weak, nonatomic) IBOutlet UITableView *sidetableView;
@property (strong, nonatomic) NSMutableArray *myFriendData;
@property (weak, nonatomic) IBOutlet UITableView *neighboursView;
@property (strong, nonatomic) NSMutableArray *friendData;
@property (strong, nonatomic) NSMutableArray *neighbourData;

@property (strong, nonatomic) IBOutlet UITableView *friendsView;

视图控制器.m

- (UITableViewCellEditingStyle)tableView:(UITableView *)tableView editingStyleForRowAtIndexPath:(NSIndexPath *)indexPath {
    if (tableView == self.sidetableView) {
        return UITableViewCellEditingStyleDelete;
    }

    if (tableView == self.friendsView) {
        return UITableViewCellEditingStyleDelete;
    }

    else {
        return UITableViewCellEditingStyleNone;
    }
}

- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{

    if (editingStyle == UITableViewCellEditingStyleDelete) {

        if (tableView == self.friendsView) {

            NSMutableDictionary *nodeData = [[self.friendData objectAtIndex:indexPath.row] mutableCopy];

            NSString *nid = [nodeData objectForKey:@"nid"];
            [nodeData setObject:nid forKey:@"nid"];


            [self.friendData removeObjectAtIndex:indexPath.row];

            [tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationFade];



            [DIOSNode nodeDelete:nodeData success:^(AFHTTPRequestOperation *operation, id responseObject) {
                NSLog(@"node deleted!");
            } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
                NSLog(@"could not delete node!");
            }];


        } else {

        NSMutableDictionary *nodeData = [[self.myFriendData objectAtIndex:indexPath.row] mutableCopy];

        NSString *nid = [nodeData objectForKey:@"nid"];
        [nodeData setObject:nid forKey:@"nid"];
        NSLog(@"%@",nid);

        [self.myFriendData removeObjectAtIndex:indexPath.row];

        [tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationFade];



        [DIOSNode nodeDelete:nodeData success:^(AFHTTPRequestOperation *operation, id responseObject) {
            NSLog(@"node deleted!");
        } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
            NSLog(@"could not delete node!");
        }];



        }

    }
    }

控制台 self.friendData：

This is the frienddata (
        {
        address2 = "street";
        body = "nfkkdkckmfkekxkx\n";
        childrenunder = No;
        city = "<null>";
        "emergency facility" = Yes;
        friendphoto = "files/stored/1504910599.jpg";
        nid = 1796;
        "node_title" = "josh";
        phone = 2369893091;
        "postal code" = V;
        "property type" = House;
        "special skills" = "med";
        "star rating" = 1;
        supervision = No;
        uid = 47;
        uid2 = 182;
    }

Answer 1

我不知道最后一条评论发生了什么，但这就是我所看到的问题的根源。

当您从 AFNetworking（或基本上任何网络框架）接收数据时，您会得到NSArray *，而不是NSMutableArray *。

当您使用时，NSMutableArray *mutArray = (NSMutableArray *) someArray;您只是强制转换该元素，但它仍然是一个NSArray *. 这就是它崩溃的原因。

你应该使用NSMutableArray *mutArray = [someArray mutableCopy];它来创建一个实际的 NSMutableArray并将其分配给变量。