我更喜欢在没有代表和片段的情况下进行。它可以通过自定义init或设置可选值来完成。

1.自定义初始化

class ViewControllerA: UIViewController {
  func openViewControllerB() {
    let viewController = ViewControllerB(string: "Blabla", completionClosure: { success in
      print(success)
    })
    navigationController?.pushViewController(animated: true)
  }
}

class ViewControllerB: UIViewController {
  private let completionClosure: ((Bool) -> Void)
  init(string: String, completionClosure: ((Bool) -> Void)) {
    self.completionClosure = completionClosure
    super.init(nibName: nil, bundle: nil)
    title = string
  }

  func finishWork() {
    completionClosure()
  }
}

2.可选变量

class ViewControllerA: UIViewController {
  func openViewControllerB() {
    let viewController = ViewControllerB()
    viewController.string = "Blabla"
    viewController.completionClosure = { success in
      print(success)
    }
    navigationController?.pushViewController(animated: true)
  }
}

class ViewControllerB: UIViewController {
  var string: String? {
    didSet {
      title = string
    }
  }
  var completionClosure: ((Bool) -> Void)?

  func finishWork() {
    completionClosure?()
  }
}

我见过很多人使用didSelectRowAtPath方法过度复杂化。我在示例中使用核心数据。

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{

    // This solution is for using Core Data
    YourCDEntityName * value = (YourCDEntityName *)[[self fetchedResultsController] objectAtIndexPath: indexPath];

    YourSecondViewController * details = [self.storyboard instantiateViewControllerWithIdentifier:@"nameOfYourSecondVC"]; // Make sure in storyboards you give your second VC an identifier

    // Make sure you declare your value in the second view controller
    details.selectedValue = value;

    // Now that you have said to pass value all you need to do is change views
    [self.navigationController pushViewController: details animated:YES];

}

方法内的四行代码就完成了。

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")
    }

}

我目前正在通过一个名为MCViewFactory的项目为这个问题的开源解决方案做出贡献，这个项目可以在这里找到：

Manticore iOS视图工厂

其想法是模仿Android的意图范式，使用全局工厂来管理您正在查看的视图，并使用“意图”在视图之间切换和传递数据。所有文档都在GitHub页面上，但这里有一些亮点：

初始化工厂时，在.XIB文件中设置所有视图并在应用程序委托中注册它们。

// Register activities

MCViewFactory *factory = [MCViewFactory sharedFactory];

// The following two lines are optional.
[factory registerView:@"YourSectionViewController"];

现在，在视图控制器（VC）中，只要您想移动到新的VC并传递数据，就可以创建一个新的意图并将数据添加到其字典（savedInstanceState）中。然后，只需设置工厂的当前意图：

MCIntent* intent = [MCIntent intentWithSectionName:@"YourSectionViewController"];
[intent setAnimationStyle:UIViewAnimationOptionTransitionFlipFromLeft];
[[intent savedInstanceState] setObject:@"someValue" forKey:@"yourKey"];
[[intent savedInstanceState] setObject:@"anotherValue" forKey:@"anotherKey"];
// ...
[[MCViewModel sharedModel] setCurrentSection:intent];

所有符合此要求的视图都需要是MCViewController的子类，它允许您重写新的onResume:方法，允许您访问传入的数据。

-(void)onResume:(MCIntent *)intent {
    NSObject* someValue = [intent.savedInstanceState objectForKey:@"yourKey"];
    NSObject* anotherValue = [intent.savedInstanceState objectForKey:@"anotherKey"];

    // ...

    // Ensure the following line is called, especially for MCSectionViewController
    [super onResume:intent];
}

这是一个非常棒的教程，适合任何想要的人。下面是示例代码：

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    if ([segue.identifier isEqualToString:@"myIdentifer]) {
        NSIndexPath *indexPath = [self.tableView indexPathForSelectedRow];
        myViewController *destViewController = segue.destinationViewController;
        destViewController.name = [object objectAtIndex:indexPath.row];
    }
}

在我的例子中，我使用了一个单例类，它可以作为一个全局对象，允许访问应用程序中几乎所有地方的数据。

第一件事是构建一个单例类。请参考页面我的Objective-C单例应该是什么样子？。

为了使对象全局可访问，我只需将其导入appName_Prefix.pch中，该程序用于在每个类中应用import语句。

为了访问和使用这个对象，我简单地实现了一个类方法来返回共享实例，该实例包含自己的变量。