Question

我有一个对象数组。我想选择那些子组并将其传递给detailView。

我在使用didSelectRowAtIndexPath或prepareForSegue

之间陷入困境

这是didSelect的主要代码：

-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    NSMutableArray *tempArray = [NSMutableArray new];
    tempArray = [mainArray objectAtIndex: indexPath.row];
    NSString *numberString = [tempArray valueForKey:@"number"];


    NSManagedObjectContext *context = [self managedObjectContext];
    NSEntityDescription *entityDescription = [NSEntityDescription
                                              entityForName:@"MyEntity" inManagedObjectContext:context];
    NSFetchRequest *request = [[NSFetchRequest alloc] init];
    [request setEntity:entityDescription];
    NSPredicate *predicate = [NSPredicate predicateWithFormat:@"number =[c] %@",numberString];
    [request setPredicate:predicate];
    [request setIncludesSubentities:NO];
     NSError *error = nil;
    NSArray *array = [context executeFetchRequest:request error:&error];

    selectedObjects = [array mutableCopy];
   NSLog(@"selectedObjects: %@", selectedObjects); << -- this looks ok

    detailsViewController = [[DetailsViewController alloc] init];
    detailsViewController.selectedObjects = selectedObjects;

    [self performSegueWithIdentifier:@"mainToDetails" sender:self.view];
}

在此示例中，selectedObjects显示正常。当我到达detailView时，selectedObjects为null。

NSIndexPath *path = [mainTable indexPathForSelectedRow];

    NSMutableArray *tempArray = [NSMutableArray new];
    tempArray = [main objectAtIndex: path]; << this isn't right.

感谢任何帮助。

Answer 1

它是零，因为您使用从未出现在屏幕上的alloc init创建了一个控制器实例。由于您正在使用segue，segue会创建新实例，您应该在prepareForSegue中传递数据，您可以使用segue.destinationViewController获取对此控制器的引用。

Answer 2

如果你想使用didSelectRowAtIndexPath替换这一行

detailsViewController = [[DetailsViewController alloc] init];

以下行

detailsViewController = [self.storyBoard instantiateViewControllerWithIdentifier:@"YOUR STORYBOARD_ID"];
detailsViewController.selectedObjects = selectedObjects;
[self.navigationController pushViewController:detailsViewController animated:YES];

IOS - 选择一个复合数组并将其传递给另一个ViewController

2 个答案: