ios 视图数据传递

1.从源视图到目的视图的数据传输

Storyboards make it easy to pass data from one scene to another via the prepareForSegue:sender: method of the UIViewController class. This method is called when the first scene (the source) is about to transition to the next scene (the destination). The source view controller can implementprepareForSegue:sender: to perform setup tasks, such as passing information to the destination view controller about what it should display in its table view. Listing 3-1 shows one implementation of this method.

Passing data to a destination view controller

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender

{

  if ([[segue identifier] isEqualToString:@"ShowDetails"]) {

    MyDetailViewController *detailViewController = [segue destinationViewController];

    NSIndexPath *indexPath = [self.tableView indexPathForSelectedRow];

    detailViewController.data = [self.dataController objectInListAtIndex:indexPath.row];

  }

}

2.从目地视图到源视图的数据传输

A segue represents a one-way transition from a source scene to a destination scene. One of the consequences of this design is that you can use a segue to pass data to a destination, but you can’t use a segue to send data from a destination to its source. To solve this problem, you create a delegate protocol that declares methods that the destination view controller calls when it needs to pass back some data.

@protocol MyAddViewControllerDelegate <NSObject>

- (void)addViewControllerDidCancel:(MyAddViewController *)controller;

- (void)addViewControllerDidFinish:(MyAddViewController *)controller data:(NSString *)item;

@end

- (void)addViewControllerDidCancel:(MyAddViewController *)controller {

  [self dismissViewControllerAnimated:YES completion:NULL];

}

- (void)addViewControllerDidFinish:(MyAddViewController *)controller data:(NSString *)item {

  if ([item length]) {

[   self.dataController addData:item];

    [[self tableView] reloadData];

  }

  [self dismissViewControllerAnimated:YES completion:NULL];

}

 

出处

http://developer.apple.com/library/ios/#documentation/UserExperience/Conceptual/TableView_iPhone/TableViewAndDataModel/TableViewAndDataModel.html#//apple_ref/doc/uid/TP40007451-CH5-SW4