Question

我收到以下错误消息： - [MPConcreteMediaItem isEqualToString:]：无法识别的选择器已发送到实例...

我正在从媒体选择器创建一个NSMutable歌曲数组到一个名为“array”的数组中。此数组在tableview（myTable）中正确显示。然而，当我尝试转向细节视图并将歌曲标题发送到本教程后面的详细视图上的标签时。我收到上面的崩溃和错误消息。

感谢任何帮助，谢谢！

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {

    if ([[segue identifier] isEqualToString:@"detailView"]) {

    NSIndexPath *indexPath = [self.myTable indexPathForSelectedRow];

    DetailViewController *vc = [segue destinationViewController];

    vc.trackName = [array objectAtIndex:indexPath.row];

    //crashes -[MPConcreteMediaItem isEqualToString:]: unrecognized selector sent to instance

    }

}

- (void)mediaPicker:(MPMediaPickerController *)mediaPicker didPickMediaItems:(MPMediaItemCollection *)mediaItemCollection {

    [array addObjectsFromArray:mediaItemCollection.items];

    [myTable reloadData];

    // mediaItemCollection = nil;

    [mediaPicker dismissViewControllerAnimated:YES completion:nil];

}

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

    //this method is called to fill out table with data

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"Cell"];

    if (cell == nil) {

    cell = [[UITableViewCell alloc]

    initWithStyle:UITableViewCellStyleDefault

    reuseIdentifier:@"Cell"];

}

    // Configure the cell

    anItem = nil;

    anItem = [array objectAtIndex:indexPath.row];

    cell.textLabel.text = [anItem valueForProperty:MPMediaItemPropertyTitle];

    cell.accessoryType = UITableViewCellAccessoryDetailDisclosureButton;

    return cell;

}

Answer 1

错误看起来就像你没有在字符串对象上调用'isEqualToString：'...哪个超类有MPConcreteMediaItem

Xcode Storyboard segue将歌曲标题从数组传递到详细视图控制器

1 个答案: