在ios，目标c中进行导航时，即使在分配之后，数据也为零。

Question

我试图将文本值、图像和uitextview从一个视图控制器传递到另一个视图控制器。但即使在完成任务后，这些值仍为零。

执行赋值语句后，titellabel、imageView和descriptionView为空。我已经分配并初始化了DetailsViewController，但在赋值后，这些值仍然显示为零。你能说出我在这里错过了什么吗？为什么他们不接受所分配的值。

- (void) tableView: (UITableView *) tableView didSelectRowAtIndexPath: (NSIndexPath *) indexPath {
    //DetailsViewController *view = [[DetailsViewController alloc]init];
    DetailsViewController *view = [[DetailsViewController alloc] initWithNibName:@"DetailsViewController" bundle:nil];
    NSLog([[self.xmlNews objectAtIndex:indexPath.row] objectForKey:@"title"]);
    view.titleLabel.text = [[self.xmlNews objectAtIndex:indexPath.row] objectForKey:@"title"];
    view.imageView.image = [self.images objectAtIndex:indexPath.row];

    view.descriptionView.text = [[self.xmlNews objectAtIndex:indexPath.row] objectForKey:@"description"];
    [self.navigationController pushViewController:view animated:TRUE];
}

Answer 1

纳文·RAM

在加载viewComponment属性之前，不能设置它们。

view.titleLabel.text = [[self.xmlNews objectAtIndex:indexPath.row] objectForKey:@"title"];
view.imageView.image = [self.images objectAtIndex:indexPath.row];
view.descriptionView.text = [[self.xmlNews objectAtIndex:indexPath.row] objectForKey:@"description"];

上述三个语句将设置尚未加载的textLabel、textView和UIImageView属性，因此它将永远不会出现。

你能做的是：

声明三个属性，一个用于保存字符串，一个用于保存图像，另一个用于在DetailsViewController.h中保存DetailsViewController.h

让我们称他们为

@property (nonatomic,strong) NSString *title;
@property (nonatomic,strong) UIImage *passedImage;
@property (nonatomic,strong) NSString *descriptionText;

将索引路径上的行修改为

- (void) tableView: (UITableView *) tableView didSelectRowAtIndexPath: (NSIndexPath *) indexPath {
    //DetailsViewController *view = [[DetailsViewController alloc]init];
    DetailsViewController *view = [[DetailsViewController alloc] initWithNibName:@"DetailsViewController" bundle:nil];
    NSLog([[self.xmlNews objectAtIndex:indexPath.row] objectForKey:@"title"]);
    view.title = [[self.xmlNews objectAtIndex:indexPath.row] objectForKey:@"title"];
    view.passedImage = [self.images objectAtIndex:indexPath.row];
    view.descriptionText = [[self.xmlNews objectAtIndex:indexPath.row] objectForKey:@"description"];
    [self.navigationController pushViewController:view animated:TRUE];
}

最后，在ViewDidLoad of DetailsViewController中，将图像和标签设置为

self.titleLabel.text = self.title;
self.imageView.image = self.passedImage;
self.descriptionView.text = self.descriptionText;

希望它能帮上忙