苹果公司的一种方法是使用Segues。您需要使用prepareForSegue（）函数。

有很多很棒的教程，这里有一个：释放你的内部应用程序开发人员第21部分：在控制器之间传递数据

此外，请阅读有关使用segues的Apple文档：使用Segues

如果要将数据从一个控制器传递到另一个控制器，请尝试以下代码：

文件FirstViewController.h

@property (nonatomic, retain) NSString *str;

SecondViewController.h

@property (nonatomic, retain) NSString *str1;

文件FirstViewController.m

- (void)viewDidLoad
   {
     // Message for the second SecondViewController
     self.str = @"text message";

     [super viewDidLoad];
   }

-(IBAction)ButtonClicked
 {
   SecondViewController *secondViewController = [[SecondViewController alloc] initWithNibName:@"SecondViewController" bundle:nil];
   secondViewController.str1 = str;
  [self.navigationController pushViewController:secondViewController animated:YES];
 }

要将数据从一个视图控制器（VC）发送到另一个，请使用以下简单方法：

YourNextVC *nxtScr = (YourNextVC*)[self.storyboard  instantiateViewControllerWithIdentifier:@"YourNextVC"];//Set this identifier from your storyboard

nxtScr.comingFrom = @"PreviousScreen"l
[self.navigationController nxtScr animated:YES];

我建议使用块/闭包和自定义构造函数。

假设您必须将字符串从FirstViewController传递到SecondViewController。

您的第一个视图控制器。

class FirstViewController : UIViewController {

    func moveToViewControllerB() {

        let second_screen = SecondViewController.screen(string: "DATA TO PASS", call_back: {
            [weak self] (updated_data) in
            ///This closure will be called by second view controller when it updates something
        })
        self.navigationController?.pushViewController(second_screen, animated: true)
    }


}

第二个视图控制器

class SecondViewController : UIViewController {

    var incoming_string : String?
    var call_back : ((String) -> Void)?

    class func screen(string: String?, call_back : ((String) -> Void)?) -> SecondViewController {

        let me = SecondViewController(nibName: String(describing: self), bundle: Bundle.main);
        me.incoming_string = string
        me.call_back = call_back
        return me
    }

    // Suppose its called when you have to update FirstViewController with new data.
    func updatedSomething() {

        //Executing block that is implemented/assigned by the FirstViewController.
        self.call_back?("UPDATED DATA")
    }

}

我找到了最简单、最优雅的版本，带有传递块。让我们将等待返回数据的视图控制器命名为“A”，将返回的视图控制器称为“B”。在本例中，我们希望获得两个值：第一个是Type1，第二个是Type2。

假设我们使用Storyboard，第一个控制器设置回调块，例如在segue准备期间：

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    if ([segue.destinationViewController isKindOfClass:[BViewController class]])
    {
        BViewController *viewController = segue.destinationViewController;

        viewController.callback = ^(Type1 *value1, Type2 *value2) {
            // optionally, close B
            //[self.navigationController popViewControllerAnimated:YES];

            // let's do some action after with returned values
            action1(value1);
            action2(value2);
        };

    }
}

和“B”视图控制器应声明回调属性BViewController.h：

// it is important to use "copy"
@property (copy) void(^callback)(Type1 *value1, Type2 *value2);

在实现文件BViewController.m中，当我们有了所需的值以返回回调时，应该调用：

if (self.callback)
    self.callback(value1, value2);

需要记住的一点是，使用块通常需要管理强引用和弱引用，如这里所述

使用通知中心

对于Swift 3

let imageDataDict:[String: UIImage] = ["image": image]

// Post a notification
NotificationCenter.default.post(name: NSNotification.Name(rawValue: "notificationName"), object: nil, userInfo: imageDataDict)
// `default` is now a property, not a method call

// Register to receive notification in your class
NotificationCenter.default.addObserver(self, selector: #selector(self.showSpinningWheel(_:)), name: NSNotification.Name(rawValue: "notificationName"), object: nil)

// Handle notification
func showSpinningWheel(_ notification: NSNotification) {
    print(notification.userInfo ?? "")
    if let dict = notification.userInfo as NSDictionary? {
        if let id = dict["image"] as? UIImage {
            // Do something with your image
        }
    }
}

对于Swift 4

let imageDataDict:[String: UIImage] = ["image": image]

// Post a notification
NotificationCenter.default.post(name: NSNotification.Name(rawValue: "notificationName"), object: nil, userInfo: imageDataDict)
// `default` is now a property, not a method call

// Register to receive notification in your class
NotificationCenter.default.addObserver(self, selector: #selector(self.showSpinningWheel(_:)), name: NSNotification.Name(rawValue: "notificationName"), object: nil)

// Handle notification
@objc func showSpinningWheel(_ notification: NSNotification) {
    print(notification.userInfo ?? "")
    if let dict = notification.userInfo as NSDictionary? {
        if let id = dict["image"] as? UIImage {
            // Do something with your image
        }
    }
}