iphone – 如何将值传递给父视图控制器？

在第二个视图控制器h文件中：

@protocol SecondViewControllerDelegate <NSObject>
- (void)addItemViewController:(id)controller didFinishEnteringItem:(NSString *)item;
@end

@interface SecondPageViewController : UIViewController <UITextViewDelegate>
{
     NSString *previouslyTypedInformation;
}

@property (weak,nonatomic) IBOutlet UITextView *textView;
@property (nonatomic) NSString *previouslyTypedInformation;
@property (nonatomic,weak) id <SecondViewControllerDelegate> delegate;

在第二个视图中,控制器m文件确保合成属性并添加然后添加：

- (IBAction)done:(id)sender
{
     NSString *itemToPassBack = self.textView.text;
     NSLog(@"returning: %@",itemToPassBack);
     [self.delegate addItemViewController:self didFinishEnteringItem:itemToPassBack];
     //dismiss modal view controller here
}

然后在第一个视图中控制器h文件将其设置为委托：

@interface FirstPageViewController: UIViewController <SecondViewControllerDelegate>
 @property (nonatomic) NSString *returnedItem;

然后在第一个视图控制器的m文件中合成并添加方法：

- (void)addItemViewController:(SecondPageViewController *)controller didFinishEnteringItem:    (NSString *)item
{
    //using delegate method,get data back from second page view controller and set it to property declared in here
    NSLog(@"This was returned from secondPageViewController: %@",item);
    self.returnedItem=item;

    //add item to array here and call reload
}

现在你有了返回的文字！您可以在第一个视图控制器的viewDidLoad中将字符串添加到数组中并调用

[self.tableView reloadData];

它应该工作.