iphone – 如何在Objective-C中的视图控制器之间传递对象？

所以在你的AppDelegate中：

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions 
{
  // the app delegate doesn't keep a reference this,it just passes it to the 
  // view controllers who retain the data (and it goes away when both have been released)
  NSMutableDictionary * commonData = [[NSMutableDictionary new] autorelease];

  // some method to parse the JSON and build the dictionary
  [self populateDataFromJSON:commonData];

   // each view controller retains the pointer to NSMutableDictionary (and releases it on dealloc)
   self.m_viewControllerOne = [[[UIViewControllerOne alloc] initWithData:commonData] autorelease];
   self.m_viewControllerTwo = [[[UIViewControllerTwo alloc] initWithData:commonData] autorelease];
}

并在各自的UIViewControllerOne和UIViewControllerTwo实现中

- (id)initWithData:(NSMutableDictionary*)data
{
    // call the base class ini
    if (!(self=[super init]))
        return nil;

    // set your retained property
    self.sharedData = data;
}

// don't forget to release the property
- (void)dealloc {
    [sharedData release];
    [super dealloc];
}