ios - NSURL 未在 View Controller 之间传递

Question

我正在一个 View Controller 中创建一个 NSURL ，然后在另一个 View Controller 中使用它。 URL 在创建它的 View Controller 中包含正确的字符串，但在我将其传递到的 View Controller 中，它是 NULL。

NSData *data = feed.imageData;

NSData *stringData = feed.urlString;
self.stringForURL = [[NSString alloc] initWithData:stringData encoding:NSUTF8StringEncoding];
self.stringForURL = [self.stringForURL stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
self.finalURL = [NSURL URLWithString:self.stringForURL];

这是我将其传递给另一个 View Controller 的地方:

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
        NSManagedObject *object = [[self fetchedResultsController] objectAtIndexPath:indexPath];

        // Code to create detailed view and set properties
        DetailViewController *detailViewController = [[DetailViewController alloc] init];
        detailViewController.managedObjectContext = self.managedObjectContext;
        detailViewController.managedObject = object;
        NSLog(@"Here is the final URL:%@", [self.finalURL absoluteString]);
        detailViewController.finalURL = self.finalURL;


        DetailViewController *detailsViewController = [[DetailViewController alloc] init];
        [self.navigationController pushViewController:detailsViewController animated:YES];

}

在 secondaryviewcontroller.h 中:

@property (strong, nonatomic) NSURL *finalURL;

在 secondaryviewcontroller.m 中:

AVAsset *asset = [AVURLAsset URLAssetWithURL:self.finalURL options:nil];

Answer 1

您做的是正确的，但是您又创建了一个 detailViewController 实例并将其推送。

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    NSManagedObject *object = [[self fetchedResultsController] objectAtIndexPath:indexPath];

    // Code to create detailed view and set properties
    DetailViewController *detailViewController = [[DetailViewController alloc] init];
    detailViewController.managedObjectContext = self.managedObjectContext;
    detailViewController.managedObject = object;
    NSLog(@"Here is the final URL:%@", [self.finalURL absoluteString]);
    detailViewController.finalURL = self.finalURL;


    [self.navigationController pushViewController: detailViewController animated:YES];

}