如何从委托获取值并重新加载视图

Question

我正在开发一个 iPad 应用程序，这是我第一次充分利用弹出窗口视图。我使用弹出窗口视图作为带有类别的菜单，并且只有 1 个带有视频的屏幕。当用户选择一个类别时，“FeaturedViewController”必须使用新的 playlistId 重新加载视图。

当用户选择一个类别时，很容易做到： double playlistId = [[playlists.items objectAtIndex:indexPath.row] playlistId];

但是如何在我的FeaturedViewController中获取该playlistId并重新加载视图？

Answer 1

在您的FeaturedViewController.m

- (void)viewDidLoad 
{
     //create reference of your delegate
    YourAppDelegate rootApp = (YourAppDelegate *)[[UIApplication sharedApplication]delegate];

     double playlistId = [[[[rootApp playlists] items] objectAtIndex:indexPath.row] playlistId ];
    [super viewDidLoad];
}

EDITED

中或者您可以在FeaturedViewController中定义一个属性并在此VC中赋值，例如：

FeaturedViewController  nextView = [[FeaturedViewController alloc] initWithNibName:@"FeaturedViewController" bundle:nil];
 //below lineset the value of property and you can pass value to nextView
    nextView.playlistId = [[playlists.items objectAtIndex:indexPath.row] playlistId]; ;
    [self.navigationController pushViewController:nextView animated:YES];

希望它能给您提供访问委托变量的想法

Answer 2

看：

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
// load new playlist
BCPlaylist *playlist = (BCPlaylist *) [playlists.items objectAtIndex:indexPath.row];
NSNumber *key = [NSNumber numberWithDouble:playlist.playlistId];
NSLog(@"Key: %@", key);
FeaturedViewController *nextView = [[FeaturedViewController alloc] initWithNibName:nil bundle:nil];
nextView.PLID = key;
[self.navigationController pushViewController:nextView animated:YES];
[nextView release];
}

Key NSlogs 正确，但我根本没有从 FeaturedViewController 中的 nextView.PLID 得到响应。