ios - 数据未传输到下一个 View Controller

Question

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {

    NSLog((@"This is didSelectRowAtIndexPAth"));
    DetailViewController *detailViewController = [[DetailViewController alloc] init];
    detailViewController.myDictionary = [self.placeArray objectAtIndex:[indexPath row]];

    /* The below NSlog is showing the content , its not null still in next viewcontroller same variable showing null content*/

    NSLog(@"My Dictionary: This is a MasterView%@",detailViewController.myDictionary);
    [self performSegueWithIdentifier:@"showDetail" sender:self];
}

Answer 1

这是因为您的 DetailViewController 实例与您手动创建的实例不同。您应该自己呈现新的 ViewController(模态或通过推送)，或者实现 prepareForSegue 方法并在那里设置字典。

编辑:

两种解决方案:

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    DetailViewController *detailViewController = [[DetailViewController alloc] init];
    detailViewController.myDictionary = [self.placeArray objectAtIndex:[indexPath row]];

    // If it is a modal
    [self presentViewController:detailViewController animated:YES];
}

或

@implementation MyClass {
    NSIndexPath *selectedCellIndexPath;
}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {

    NSLog((@"This is didSelectRowAtIndexPAth"));
    selectedCellIndexPath = indexPath;

    [self performSegueWithIdentifier:@"showDetail" sender:self];
}

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    if ([segue.identifier isEqualToString:@"showDetail"]) {
        DetailViewController *detailViewController = (DetailViewController *)segue.destinationViewController;
        detailViewController.myDictionary = [self.placeArray objectAtIndex:selectedCellIndexPath.row];
    }
}